tbh it all comes down to the record label and how risky they are. you make a track. send it to a label and let them know where the samples have come from. From here 3 things can happen 1. They risk it, sign the track and release it and hope the owner dosent catch on, which happens alot. 2. They contact the owner and discuss the use and what royalties will be paid. 3. They send the track back to you and tell you to replace it with something else. also. Think of the 'think' breakbeat, people have used that break in 100's of songs and i dont think lyn collin's gets royalties. also with making bootlegs there is a bit of grey area. technically if you aernt making money off of it you are fine, but people can claim that your remix has taken focus off their product therefore causing them a loss in sales and a bunch of other technical shit like that. basically if you make a bootleg and get stung for it, youve sampled someone who is friends with good lawyers and they found out about it on a really shitty day for them, would have to be extremely unlucky