They Block Everything
Although it might seem that blocking anything and everything is the best move for companies, it really isn't. Frustrated employees aren't doing companies any good. Whether employees admit it or not, they aren't spending eight hours of their day working. At points throughout the day, they're trying to find sites to get away from work. If every site they would want to browse are blocked, they might engage in dangerous practices if they find a way around the blockade. Believe it or not, giving users access to Twitter really is a good idea.