[rrrx3]

There are clear, well-defined rules around what constitutes a political advertisement, published by the FEC. Some states have guidelines that go further. A smart place to start, instead of feigned ignorance or poorly constructed strawman arguments, might be there.

https://www.fec.gov/help-candidates-and-committees/making-di...

[tomohawk]

The rules are not clear or well defined, and often result in litigation. Often, what becomes determinitive is the context around the ad or the situation of the entity placing it, and not the ad itself. So, to do this Facebook would also have to track entities, etc.