The 10th comment claims that in order to remove annoying “Constant Guard” pop-ups, Comcast is demanding the user sign up for a $4.95 per month “Signature Service.” It is quite possible that this is not a corporate-wide ploy and is practiced by a few unethical representatives.
Recently, when changing my long distance carrier with Qwest (my local provider), I was advised that if I didn't want a long distance provider and someone made a long distance call, any provider can take it and charge what they want, so I would be better off paying Quest two bucks a month for their long distance service. I asked to simply block long distance and was told that would be four bucks a month! A subsequent call resulted in a different result. I got long distance blocking for no fee.
If Comcast is using their “Constant Guard” service to hold machines hostage and convert free customers to paying subscribers, I would expect some serious problems for Comcast. If this is not Comcast's policy, then Comcast had better hurry up and quickly figure out how to prevent unethical support representatives from deceiving users.