It's fair game according to the definition at the beginning of the OP, but when gaming human-made real-world rules, one should be aware that if it works, and it's against the intention of the rules, the rules are likely to be changed to prevent it. There's a certain amount of anti-inductiveness in the activity. See the running battle between tax legislators and tax accountants, which has recently come to public attention in the UK with the news that the UK operations of Starbucks, Google, and Apple apparently make hardly any profit to be taxed on.
(Disclaimer: I work for Google, there's been informal internal discussions.)
What seems like it might be going on isn't that Google et. al are doing anything unusual, so much as they're taking advantage of loopholes that may have been established for the benefit of other industries, without paying off the politicians. The reasonable thing to do would be to change the laws, not to target individual companies.
I can't say I'm very familiar with the details, though.
Thus spake Eliezer:
It seems that many here might have outlandish ideas for ways of improving our lives. For instance, a recent post advocated installing really bright lights as a way to boost alertness and productivity. We should not adopt such hacks into our dogma until we're pretty sure they work; however, one way of knowing whether a crazy idea works is to try implementing it, and you may have more ideas than you're planning to implement.
So: please post all such lifehack ideas! Even if you haven't tried them, even if they seem unlikely to work. Post them separately, unless some other way would be more appropriate. If you've tried some idea and it hasn't worked, it would be useful to post that too.