My employer has an electronic communications policy that forbids employee's from participating in the company's social networking sites unless it is their job to do so. We can't "like" their posts, or respond to tweets etc. I work in the financial industry, and the company is very protective of their credibility. We do have an internal social networking site to promote collaboration.

I think any company that tries to "stuff the ballot box" by making employees sign up for accounts is barking up the wrong tree. They'll have an active looking social networking presence, but it won't yield the benefits that having a real community of clients will.

I was reading Delete by Viktor Mayer-Schonberger recently and he has a very simple solution... put expiration dates on all data. I don't know that it's a basic human right to be forgotten, but it's pretty harsh to have a picture of one act of foolishness follow you around for 20 years.