I would like to take this moment to cross link the frequent "Your employer checks your online life on Facebook/Twitter etc." media scares with the gross Domino's employee video.
The point of the scare stories always seems to lie in the perceived asymmetry between the employed individual and the BigCo Facebook-checkers. The asymmetry, according to the typical story, makes keeping up with people 'unfair' and presumably the mass of the corporation makes the check easier to do. It's not just somebody you're about to have a conversation with trying to get a feel for who you are, but BigCo surveillance (we all know that stuff is relentless and 24/7 and impossible to sleep during).
On the other hand the Domino's story tells us that the corporations simply have to. The asymmetry cuts both ways; two random employees can have the same media impact as all of the organization of BigCo combined.
So in fact the asymmetry isn't there at all, except in cost. It's really expensive for BigCo to maintain any kind of assurance that the conversation about BigCo stays civil. In terms of impact, independents have the upper hand.