The spell Scrying states:
On a failed save, the spell creates an invisible sensor within 10 feet of the target. You can see and hear through the sensor as if you were there. The sensor moves with the target, remaining within 10 feet of it for the duration. A creature that can see invisible objects sees the sensor as a luminous orb about the size of your fist.
What can someone who is being scryed actually do to this sensor if they can see it? Can they destroy it? Dispel it? Or can they do nothing except gain the knowledge that they are under surveillance?
(Clairvoyance has identical wording, and Arcane Eye does something very similar, except it is an “eye” rather than a “sensor” – so it’s likely the answer would apply to these spells too.)