For a lot of environmental regulations, whether or not a permit is needed is most of the question.
In the US, if you want to build a shed in the middle of a wetland, you need to go through an arduous permitting process and are unlikely to gain approval. If you want to build it within 100 feet, you can probably do it, but you need to confer with the relevant DEC to show that you won't negatively impact the wetland during construction. If you're more than 100 feet away, you don't even need to talk to the DEC, because you're not in protected land.
Of course, if the DEC decides they don't think your shed is outside the 100 ft adjacent area, they may decide to do a demarcation and figure out exactly where your shed is relative to the wetland, and if you messed up you're in trouble. But if they send out a biologist to demarcate the wetland and you're far enough away, you're fine.
So many people, if they think it's ambiguous, will take the time to go through an abbreviated permitting process to get a certificate of "no permit needed", to save themselves the headache later on.
If you go through a process like this, chances are people with local expertise will tell you you're wasting your time -- the case looks pretty clear cut, and hardly anyone ever has trouble in such circumstances. The clerk at the department responsible for issuing the "no permit needed" certificate may tell you you're wasting everyone's time.
But if you're a big corporation like Google, you don't really have an excuse not to do it. You can afford the lawyers, you can afford to plan years in advance, and so many more people are going to notice if you skip steps. Even if you end up being in the legal clear, no permit was needed, you're so much better off getting it in writing in advance.
