One thing just occurred to me with the whole licenses/rental thing in relation to online distributors like Steam and Origin; I don't know how true this holds for non-Steam platforms, but I do remember Valve themselves giving pretty detailed instructions on how to sort-of "share" certain games you may have on Steam with other people in a local network capacity.
Basically, they obviously don't allow one person's copy of the game to be played online by multiple people at once, but for local co-op or LAN matches and the like, you can download the game, run Steam in offline mode, and play against other copies of your own game locally. Obviously some non-Valve games that can detect the same serial key in all the copies might moan, but the other titles won't, and all of Valve's ones were made to work this way.
Kinda flies in the face of the license/rental thing... just as this post kinda flies in the face of the actual topic of the thread, but hey, it seemed relevant when I started typing