## Why does CNAME Cloaking enable cross domain tracking?

Recently, as browsers start blocking 3rd party cookies, a risky technique known as CNAME Cloaking emerged. It is said that this technique enables trackers, especially those in the online advertising industry, to continue to track users across domains and across the web.

From https://medium.com/nextdns/cname-cloaking-the-dangerous-disguise-of-third-party-trackers-195205dc522a:

Letâ€™s assume you visited website1.com that includes a third-party tracker from Tracking Company, then website2.com that also includes that tracker. Tracking Company would know that you visited both sites…

As I understand, in CNAME Cloaking, the browser doesn’t know a given external resource (such as image, iframe, or JS) is an alias to a 3rd party site. So if a user is on website1.com, the browser will still store and send first-party cookies to img1.website.com, which is an alias to trackingcompany.com.

My question is on how CNAME Cloaking establishes linkage for the same user across domains. As a specific example, say website1.com stores/sends its first-party cookie containing w1_id to Tracking Company, while website2.com sends/stores w2_id. How does Tracking Company link w1_id and w2_id it gets?

## Solve Matrix equations with Cross Product: weird system of equations

I would like to find the values {Pfx, Pfy, Pfz} that satisfy the equation A X B = C . The code of everything is at the end, I want to ilustrate with images what i think of first:

A is this:

B is this: {0,0,0}

And C is this: {100,500,200}

The image of the complete code is this one:

My variable here are {Pfx,Pfy,Pfz} and the {i,j,k} are the unit vectors. The way that the matrix is shown in the picture corresponds with a trick used to solve in papper this type of matrix.

The solution would give me the value of Pfx in the "x" coordinate (and this would be expressed by Pfx being multiplied with the i vector). And the same mechanism applies with Pfy related with j Vector ; and Pfz related with k.

The problem here comes with the fact that the I can`t find the values {Pfx, Pfy, Pfz} that satisfy the equation A X B = C. I am not sure if the problem lies in the "LinearSolve" comand, in the use of the CrossProduct or in the use of the versor {i, j, k} inside the matrix.

Any kind of help in this regard will be extreamly useful, thanks in advance!!

Code:

``i := {1, 0, 0}  j := {0, 1, 0}  k := {0, 0, 1}  LinearSolve[({ {i, j, k},{1, 2, 3},{Pfx, Pfy, Pfz}})\[Cross]({{0},{0},{0}}) == ( {{100},{500},{200}} )]    ``

## Cross Domain Tracking with Multiple GA UA Properties, Single GTM Container

I have a client who wants to route page views into separate GA Properties based off a returnUrl UTM. I am trying to configure this in one tag using one GTM container. I know that using cookies for Analytics is changing rapidly and I am having trouble getting everything set up.

Here’s how I have it configured currently:

returnUrl Trigger:

That trigger fires a Page View tag configured like so:

GTM Preview Fires Everything Correctly, and the Tracking Values are correct:

I have added the original domain to Referral Exclusion Lists on each GA Property for the returnUrl domains. But I am not getting page views.

Google Tag Assistant is giving an error of "No HTTP response detected" for the Analytics UA-ID (which is correct).

I’ve seen a lot of different blog posts and tried implementing a few. But I’d like to solve this as quickly and smoothly as possible. I appreciate the help!

Blog posts used:

This post I have looked at but it looks like a lot more Tags / Triggers are involved. Before I bite this off I want to see if there’s a way to save this configuration.

Thanks for looking!

## MongoDB cross datacenter replication without elections or high data availaility

I want to replicate a MongoDB database to another node, located in another datacenter. This is to help guard against data loss in the case of a hardware failure.

We don’t want/need high availability or elections; just a ‘close to live’ read-only copy of the database, located in another DC.

Everything I read says that you need an odd number of nodes, due to elections, but this isn’t something we need/want and I can’t find anything related to just having one primary, and one secondary (I might be being blind).

Is this something we can achieve with MongoDB, and if so are there any ‘gotchas’ or serious downsides we should consider?

## How secure is the apple cross device copy and paste feature?

I can copy and paste between my iPhone and MacBook Pro it’s a great feature that I find myself using frequently. I am frequently copy and pasting from my password manager to log in to different sites. a few questions about the security of the cross device cut and paste.

• How is apple securing this cross device copy and paste?
• Can this feature be turned off?
• Should I turn off this feature to improve my security?

## Why are cookies sent with HTML page’s cross domain requests but not with JS’s XHR?

When we write a `HTML` page with `form` tag and an `action` attribute and a submit button. As soon as we click on submit a request is sent (with cookies) to the `URL` which was the value of `action` attribute.

But if we send cross domain request to the same domain with JS’s `XHR` cookies won’t be sent.

In both cases, requests are sent to another domain but still cookies are sent with the first case only why so?

## How to calculate the power spectrum and cross spectrum for two dimensional data?

I have two sets of data:

G={{G_1,x_1,y_1},{{G_2,x_2,y_2}},…..,{G_{n},x_n,y_n}}

H={{H_1,x_1,y_1},{{H_2,x_2,y_2}},…..,{H_{n},x_n,y_n}}

where H_{n} and G_{n} are values of G and H in the point (x_{n},y_{n}). I want to calculate the power spectrum and the cross spectrum . Can you help me ? Thanks.

## How to calculate the power spectrum and cross spectrum for two dimensional data?

I have two sets of data:

G={{G_1,x_1,y_1},{{G_2,x_2,y_2}},…..,{G_{n},x_n,y_n}}

H={{H_1,x_1,y_1},{{H_2,x_2,y_2}},…..,{H_{n},x_n,y_n}}

where H_{n} and G_{n} are values of G and H in the point (x_{n},y_{n}). I want to calculate the power spectrum and the cross spectrum . Can you help me ? Thanks.

## Iterate cartesian product (cross product) of sorted lists of positive numbers in order of decreasing product of entries (MVCE of a stub included)

Suppose I have several sorted lists of positive numbers, like so for example:

``double[] a1 = new double[]{0.70, 0.20, 0.10}; double[] a2 = new double[]{0.80, 0.10, 0.05, 0.05}; double[] a3 = new double[]{0.60, 0.15, 0.14, 0.10, 0.01}; ``

I want to iterate Cartesian product of these arrays in the order of decreasing product of entries, like so:

``0000: Combo[product=3.36e-01, vals=[0.70, 0.80, 0.60], indexes=[0, 0, 0]] 0001: Combo[product=9.60e-02, vals=[0.20, 0.80, 0.60], indexes=[1, 0, 0]] 0002: Combo[product=8.40e-02, vals=[0.70, 0.80, 0.15], indexes=[0, 0, 1]] 0003: Combo[product=7.84e-02, vals=[0.70, 0.80, 0.14], indexes=[0, 0, 2]] 0004: Combo[product=5.60e-02, vals=[0.70, 0.80, 0.10], indexes=[0, 0, 3]] 0005: Combo[product=4.80e-02, vals=[0.10, 0.80, 0.60], indexes=[2, 0, 0]] ... ``

E.g. in the example above the first entry is obvious (as arrays are sorted) and it is a combination of the first values: `[0.70, 0.80, 0.60]` with product `0.70*0.80*0.60 = 3.36e-01` and corresponding value indexes in arrays `a1, a2, a3` are `[0, 0, 0]`. Now the second entry is less obvious, should we change `0.70` to `0.20`? Or `0.60` to `0.15`? Or `0.80` to `0.10`? The second should be `[0.20, 0.80, 0.60]`with product `9.60e-02`, indexes `[1, 0, 0]`.

Here is a program in java to generate/print them: https://repl.it/repls/FilthyGreatRotation (all the logic is in `printWholeCartesianProduct()` method)
This program generates them in lexicographic order and then sorts the whole set by product.

Question: Is there an easy way to actually generate the combos in correct order in the first place?

The reason for this: I don’t have the lists in the first place, only iterators over some sorted collections of numbers. Possibly veeery long, length not known ahead of time, but it is known that the numbers in each iterator are sorted.

MVCE to play with (same as in https://repl.it link above):

``import java.text.DecimalFormat; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.StringJoiner; import java.util.function.Consumer; import java.util.stream.Collectors;  public class Main {      public static void main(String[] args) {         List<List<Double>> data = createData();         printWholeCartesianProduct(data);     }      public static List<List<Double>> createData() {         double[] a1 = new double[]{0.70, 0.20, 0.10};         double[] a2 = new double[]{0.80, 0.10, 0.05, 0.05};         double[] a3 = new double[]{0.60, 0.15, 0.14, 0.10, 0.01};         return createData(a1, a2, a3);     }      public static void  printWholeCartesianProduct(List<List<Double>> data) {         final DecimalFormat df = new DecimalFormat("0.00");          // print input data         String matrix = data.stream()             .map(l -> l.stream().map(df::format).collect(Collectors.joining(", ")))             .map(row -> "[" + row + "]")             .collect(Collectors.joining("\n"));         System.out.println("Input data:\n" + matrix);          // collect combos as they are generated         final List<Combo> combos = new ArrayList<>();         Consumer<int[]> callback = indexes -> {             double[] v = new double[indexes.length];             double prod = 1;             for (int i = 0; i < indexes.length; i++) {                 List<Double> col = data.get(i);                 int index = indexes[i];                 v[i] = col.get(index);                 prod *= v[i];             }             combos.add(new Combo(prod, v, indexes.clone()));         };          // generate combos         int[] c = new int[data.size()];         int ptr = c.length - 1;         while (ptr >= 0) {             callback.accept(c);             c[ptr]++; // increment             if (c[ptr] == data.get(ptr).size()) { // carry                 do {                     ptr--;                 } while(ptr >= 0 && c[ptr] == data.get(ptr).size() - 1);                 if (ptr < 0) {                     break;                 }                 c[ptr]++;                 // zero out                 while (++ptr <= c.length - 1) {                     c[ptr] = 0;                 }                 ptr = c.length - 1;             }         }          // cheating - sort after generation and print result         combos.sort((o1, o2) -> Double.compare(o2.product, o1.product));         StringBuilder sb = new StringBuilder();         double totalP = 0;         for (int i = 0; i < combos.size(); i++) {             sb.append(String.format("%04d: ", i)).append(combos.get(i)).append("\n");             totalP += combos.get(i).product;         }         System.out.printf("Cartesian product in descending product (total p=%.3e):\n%s", totalP, sb.toString());     }      public static List<Double> asList(double[] a) {         return Arrays.stream(a).boxed().collect(Collectors.toList());     }      public static List<List<Double>> createData(double[]... arrays) {         final List<List<Double>> vals = new ArrayList<>();         Arrays.stream(arrays).forEachOrdered(a -> vals.add(asList(a)));         return vals;     }      static class Combo {         final double product;         final double[] vals;         final int[] indexes;          Combo(double product, double[] vals, int[] indexes) {             this.product = product;             this.vals = vals;             this.indexes = indexes;         }          @Override         public String toString() {             return new StringJoiner(", ", Combo.class.getSimpleName() + "[", "]")                 .add("product=" + String.format("%.2e", product))                 .add("vals=[" + Arrays.stream(vals).boxed().map(v -> String.format("%.2f", v)).collect(                     Collectors.joining(", ")) + "]")                 .add("indexes=" + Arrays.toString(indexes))                 .toString();         }     } } $$```$$ ``

## How to define a cross product of two orthogonal vectors?

t[s],n[s] and b[s] are three orthogonal vectors. I define a cross product Cross[t[s], n[s]] = b[s]. I want to calculate the cross product in the formula a2, I want a2 to have the same result as a3. How to achieve this?