What can be done to a Scrying sensor?

Question

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?

(The clairvoyance spell 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.)

Answer 1

The spell isn't clear, but we can reach conclusions based on the wording of the Clairvoyance spell.

For starters, you're not the first person to ask (see this thread on ENWorld, which unfortunately does not yield an answer), and it is, quite frankly, unclear.

I was not able to find any Sage Advice/Jeremy Crawford ruling on the question, so from there the best thing to do is to look for similarities between Scrying and similar spells, and one is an obvious choice: the 3rd level spell Clairvoyance (PHB, p. 222). It works the same way as Scrying in that you...

[...] create an invisible sensor within range in a location familiar to you...

This is the exact same wording ("invisible sensor") as used in Scrying. The description for Clairvoyance, however, is more thorough since it specifies the following:

The sensor remains in place [...] and it can't be attacked or otherwise interacted with.

From there, two possible conclusions:

• Either you consider that the wording from Clairvoyance applies to all "invisible sensors" and they cannot be attacked/interacted with, and Scrying was just a bit thin on the ground in description;
• Or you consider that WoTC purposely said so in Clairvoyance and did not include that text in Scrying because they wanted the sensor to allow interaction in the latter case.

I would probably go for the first option myself. Simply put, if the invisible sensor in Scrying was meant to be interacted with, I would expect the spell's description to explain how. As it is, the best description we have for this sensor is that it appears as a "luminous orb" for creatures able to see it, without even specifying its actual nature ("sensor" is not an item or creature type). Since we have no information on its tangibleness, weight, etc. it seems more likely that it's meant to be non-interacting.

TL;DR: Since the invisible sensor in Clairvoyance cannot be interacted with, and there is no clear explanation of what a sensor actually is, I would make the ruling that the invisible sensor in Scrying cannot be interacted with either.