I hate employers that have them, because they usually use them to get rid of people and play favortism by letting some get away with it, and nailing others on boarderline offenses.
My current employer has a ZT policy against personal phone calls and personal email. If a recruiter calls me at work, I am automatically escourted by security out the door. They record all phone calls being a help desk and have cameras everywhere, even in the bathrooms and showers (for when people work three shifts in a row and need to refresh). All I can do so far is use email, at home, and contact employers that way. If they call me, I am usually at work, and won't get home until late at night. The only time I do have is early in the morning, but most recuiters usually call after lunch for some odd reason?
I didn't say I couldn't search for a job while at this one, just that my hours for doing so are reduced. I would do better if I could call someone back 15 minutes after they called me, and not 8 hours or so later or the next day, etc. I called one the next day, and they said it was too late and they already have enough canidates to interview for the job.