It was, in my estimation, only a matter of time. I think that this is an incredibly stupid move on the RIAA's part. What next? Are they going to go after DJs for live club mashups? How about DJs with mix tapes that actually promote songs? Idiots. They don't even know who their friends are anymore. And, yes, mashup mixers are their friends as they highlight more than one tune at once, promote the tunes mashed up, and don't drain a dime from the RIAA's pockets.
Here's the word from one mashup site.