I understand that any term, grammatical or not, becomes valid if there is common usage. I'm not concerned about that.
Google and Photoshop are both commonly used as verbs. Given that the terms map fairly well to verbs (web searching and image editing), I can follow the logic of their use.
Does this work for Facebook, though? What verb is it replacing?
Best Answer
Merriam-Webster has a whole list of suggestions:
Judging by the list, you can't predict which verb "to facebook" might or might not end up replacing. Right now, it's just a shorthand for many different things to different people.