There are troubling stories of scams attacking YouTube’s ContentID system, where parties (“rights management companies”) claim to own music they did not create and scam payments from YouTube creators. Matt Binder has a story (Aug. 14) in Mashable, claiming 'This $23 million YouTube music royalties heist is a huge reminder that online copyright is deeply flawed'. The word 'heist' suggests a 'smash and grab' job right out of 'Oceans 11'. Self-published music might be more vulnerable to fraudulent claims.
Hoeg Law (of Virtual Legality) has a Monday morning jam session on the problem (the real discussion starts at the 24 minute mark).
More interesting is a story July. 1 by Morgan Sung, 'Cops are playing music during filmed encounters to game YouTube's copyright striking'.
This gets back to the idea, yes, you have the right to film the police. So police sometimes play presumably copyrighted music on a device so it will be in the background. A content creator could go to the effort of editing out the music, but then the sound (and police and subject speech in an incident) would be lost. According to the article, it is not necessarily clear that incidental background music might be allowed under Fair Use (and the CASE Act CCB could get a say at a case like this). But YouTube is likely to mark it and sometimes may log copyright strikes (although what I have read about incidental music in four outdoor instances of mu own say, no, there is no strike, just loss of revenue to the rights holder who filed; it would sound conceivable a troll could try to test the system). Moreover, a troll (non-owner) can try to file DMCA claims against such content, and these might result in (false) copyright strikes.
(Aug. 16): Leonard French reports an update on the Content-id issue (Schneider v. YouTube).