Team up with friends and create a stash of shared accounts

For paid services: isn't this directly against TOS for most of them? If this takes off, I'd imagine most services will try to add some sort of JAM detection and disable accounts in this case.

For free services: I don't understand why would I want to share my Reddit or Twitter account with my friends. Sharing a work account -- sure, this is useful. But my personal one? less so.