you dont see many cams around due to the enforcement against in theatre camming.

even teleciene versions are few in number [a way of camming in your pirate loPHt]. it seems cams were a counting coup for scene credit and its now just looked at as dangerous.

actual copying of prerelease screeners is in the mire as well. screeners basically were watermarked and sent out as promotionals so a theatre location could judge if they wanted to show them or not, and as promos in store to encourage rentals.