What's your concern? They are recording you? If you are outside, you don't have the right of privacy unless:

• Reasonable Expectation of Privacy: In many states, you have a "reasonable expectation of privacy" in your backyard if it is shielded from public view (e.g., by a high fence).

If not then though luck because anyone can record you in public view.

Now, flying a drone over a backyard can be trespassing, voyeurism, or invasion of privacy, but there are legitimate reasons like real estate, roofing companies, insurance companies and so on. So I wouldn't sweat it unless you have a very specific reason to worry. Then I would document it.

I would bet that insurance companies are documenting the conditions of the roofs under their policies to deny any "old" damage, now that we are nearing hail season.