[regulation_d]

Copyright law: A reason that copyright trolls are less common than patent trolls is that under copyright law, works created independently are not infringing. In court, you might have to prove that you did actually create the thing independently, but I think most juries would be sympathetic to this case. "Oh, you think that the defendant combed through your giant library of millions of logos to find this one specific, rather simple looking specimen."

Also, a lot of logos are simply not "artistic" enough to be eligible for copyright. So in general, logos are more likely to be the subject of trademark litigation than copyright litigation.

Trademark law: In order to claim a trademark you must have used the mark in commerce. So a catalogue of logos not used in commerce is of no real value from a trademark perspective.

[paulddraper]

+1

Copyrights are more about the process more than the product. This is why "clean-room" implementations do not violate copyright law.

Trademark is about commercial ambiguity.

[foxyv]

Usually the method of a copyright troll never reaches the jury stage. It's mostly a racquet to get people to pay you not to sue them or file vaguely legitimate DMCA takedowns on their content.

[vitiral]

It's amazing when laws make complete and consistent sense, +100 to this great answer