Probably you do not know, but some cam sites (includes our tubecamgirl) leaves the copyright to the cam girl who streams the own video. We just got a non exclusive license to temporarily stream the video while it is live, same as does skype, it is especially useful to be deemed as an internet service provider, instead of content owner, editor and publisher just in case (euro union laws, but USA is similar too).
This means that let's say you want to license some of the tubecamgirl streams (I remember Nick of crak asked me year ago, and still now he's searching for?), you should license the videos from the models and not from the site - unless for the specific case we put ourselves in the middle - but this we not do as we think it is not worth.
This also means the DMCA should be send by the cam girl (or her studio boss - agent if any) and not by the cam site, to take down screenshots or vidcaps - like this one:
https://gfy.com/showthread.php?t=1071294
In fact, if a cam girl do a skype show to a guy who post on tube, should not be skype company to send a DMCA to tube, as skype it is not the owner. Why to own something that is needed only to happen once, live? It gives only issues.
So let's say you screen capture some videos you like in tubecamgirl, you take note what the day and model, you (we) ask the model if she want sell for $XX, you pay her (directly?) and create a 2257 thing for that day and her name and ID.
In other words, this is a live content production: camgirl -> internet -> you screengrab and edit a video.
However, models often say yes... then after a while when made the site (so worked a lot with her pics) she call back and say no, remove all (they figure her pics or sample 3 min vids go in forums of romania or russia seen by her bro and the bro of her gf) and issues like this that you don't want to deal with.
So most models say no in first place - so I should ask every model beforehand "do you want to also sell cam clips for sites", then from this list keep some recordings and put them for sale... keep updated with models who change idea and say remove this and that... for a couple of buyers per year?