The fourth practice to avoid is Social Media Thought Police.
It's reasonable to block Youtube (GOOG) in the office because of the bandwidth it consumes. The recent e-mail message I received from a worker who'd just been informed of her employer's "no LinkedIn profiles permitted" policy sets a new low for organizational paranoia. Memo to your general counsel: Human beings work in your business. People have lives, brands, and connections beyond your walls, and those human entanglements are more likely to help your business than to hurt it. What to do instead: Treat people like babies only if you want them to act like babies. Let the rest of them update their LinkedIn, Facebook, and Twitter accounts appropriately, and if they're not getting their work done, deal with that problem on its own.