I get my stuff done way ahead of time and that's all that matters. It's great working at a job where you get valued by the value of work you do -- not some silly statistic of making sure every second is allocated to doing that work.
Which, all it invites is workers to take their time spending the absolute maximum time possible to get the same amount of work done. If there's no incentive in getting it done faster -- they won't.
You get paid to do XYZ. If you can still do XYZ with 3 hours of surfing a day. The company isn't losing anything. (In fact it gains, cuz during crunch time -- you of all employees are the only one who can step up and do XYZ123 in the shortest amount of time cuz you're better trained at doing things fast).