sure you could spend it surfing HN, or whatever, but you are under more pressure to produce resultsAs someone who has worked independently and for others in offices and remotely, the above statement is the exact opposite of reality.
When people are in the office non-production is perversely seen as production. Where warming a seat and having lots of busy work meetings and filling white boards full of inanity is "the gears of work".
When working remotely, the sole indicator of accomplishment is actual production. All of the bullshit is pushed aside.
We are seeing a company taking away something we - as employees - like, in addition to our $120,000 per year wages, our paid healthcare, our free office snacks and clothes washing and our free donated dairy cow.
As humorous as that is, your "heed the man" advice is quaintly archaic. A business like Yahoo is nothing but the combined work of a bunch of smart people. We've seen -- time and time again -- that many such companies are driven and succeed because of a subset of those people, so it is dangerous, dangerous ground to offend them. Because they become the upstarts that grind places like Yahoo into dust.
The world has changed. We all have the tools, the technology, the capacity to scale, the communications mediums, and the audience. It is nothing like it was.
EDIT: Places like Reddit, Digg, Slashdot are by far busiest during the North American work day. These are by and large people working in offices.