Interesting mechanism thought to limit the amount a black hole can be consumed. Current thinking is that a black hole consumes, giving off energy in the form of jets and we get a quasar. A black hole will consume, and consume and consume some more, but they eventually consume so much that the mass of the black hole and the mass of the matter they are consuming begins to force objects outside of it's pull away from it, think toilet flapper that stops water after a flush. The black hole continues to consume the matter trapped in it's gravity emitting the energy until it's consumed all of the material in it's grasp. It's then thought to go silent or inactive. It's still there waiting for material to fall into it and it'll begin feeding again. This seems plausible otherwise what would stop black holes from consuming everything?
This is the current thinking around black holes at this time.
