Trying to help people be legal when they won't even tell you who made the complaint or what the complaint was specifically about? Yeah, right. Are they aware of the number of people who think they're being jerks?Sounds like they want you to send them song titles so they can make a case. I think it's up to them to do the research. If they can't tell you what they object to, they probably don't know themselves. The song database is available to the public, and they obviouly know the URL.
You have to be found to be willfully breaking copyright laws, don't you? If you don't know you're doing it, how can it be willful? I still think they're trolling.