There's MACoS (Musicians Against the Copyright of Samples) but I don't think they have been particularly active in a while.
Some of the most brilliant electronic composers are amidst their ranks, decades ahead of their time though.
Alas, their presence on the web has been mothballed for an awfully long time. Here's an internetarchive (npub1umd…wfr7) historical cached version of their old web presence:
https://web.archive.org/web/20050602085649/http://www.icomm.ca/macos/
Less formally, there is the 2009 documentary "Copyright Criminals" featuring DJ Q*Bert et al, I own it on DVD, but I have to say the "legal advice" given, while probably well researched, doesn't contend with the reality that the for-profit music "biz" has been rife with payola and corruption for decades and that an average individual has a snowball's chance in hell at making a penny without kowtowing to some really insidious pieces of shit and all that is entailed with "selling out" as a result.
In other words, their legal recommendations are effectively useless.
Some people get away with murder, other people will make sure that your message never gets heard and it's not particularly cut and dry and all the BS around "sample clearance" and residuals and whatnot are basically only there for the honchos who are part of the corruption in the first place.