We used to have fairly free and open access to the net here at work - as long as we did the work first we could browse whatever and wherever we liked within reason, especially on night shift.
Then one or 2 of our staff had to play up - one kept downloading dodgy little "trojan" games to play, another was an avid you-tube fan, etc, and once even downloaded 3 full length movies to watch - in a single 8 hour shift!
So the poo hit the fan about 3 months ago when the big boss got a bill for a couple of hundred bucks for "excess" downloads - and we have a "large and fast" net connection here so that was some amount of downloading!
Sure enough our net access was immediately restricted to a white list system, ie you can only access web addresses that are on the permitted list,

and that's a pretty short list around here.
I approached my manager and asked for access to IceInSpace.com.au, and being a good bloke he granted it

(he is also out I.T. manager so I had access immediately). No one else here could reach any non-work related site until just this week when open net access has been restored again.

(One of the "problems" no longer works here, they've moved overseas).
The footnote to this is that I've only found out in the last few days that several other staff have been using my IceInSpace access for weeks here, browsing the forums when I'm not here because they didn't have access to anything else interesting!