The headline from O'Reilly Developer News read, "Microsoft Fires Mac Fan For Blog Photo", so I followed the link to the eclecticism > "eclecticism" weblog.
I've said it before and I'll say it again. Just because you MAY say anything you want doesn't mean that you SHOULD. In the old days, this is the sort of wisdom that imparted by one's mother or father, sometimes with the back of their hand. Was poor Michael spared the rod? If not, perhaps he'll remember to heed that advice the next time.
The same is true no matter where you work, what you do, or in what company (people, not corporation) you find yourself. The U.S. Constitution may give one the right to speak their mind, but that doesn't excuse poor judgment. Nor should anyone be surprised if forced to pay for that poor judgment. The wide freedom enjoyed by Americans requires everyone exercise a commensurate amount of responsibility. Unfortunately, the Constitution can't protect one for failure to exercise that responsibility.