How many times have you heard the following line?
"We can't go to the authorities! They'll stick you in a lab and run experiments on you for the rest of your life!"?A dozen? A hundred? It's in Smallville, Spider-Man, Eureka, all over Heroes. It's the explanation why every superhero and pseudo-superhero throughout fiction must hide their powers and not announce to the world that "Hey, I, Clark Kent, am actually an alien and have powers above and beyond that of mortal man! Isn't that cool?"
But it's, y'know, bullshit. If you woke up one day and discovered you had mysterious, extraordinary and possibly dangerous powers, wouldn't it be a good idea to go to people who could test you, explain what's happening and then help you control or possibly remove your powers? Isn't a bad idea to let a possibly rampaging green goliath wander around the general population just because Dr. Banner's scared of needles?
The "lab rat for life" line is just as bad as the "we can't go to the cops because they'll think we did it" excuse. No, if you're a suspect for a crime you didn't commit, the last thing you should do is run from the cops. You should go TO the police and explain your story in detail, so the cops can use all the information to find the real culprit. If you're really worried, bring a lawyer.
I understand why writers want to isolate their heroes, why they limit their resources and cut them off from most of society. The whole secret identity aspect of superheroes, that the seemingly mild-mannered man next to you might be hiding fantastic abilities depends on that man having a reason for hiding his powers.
But that reason has to be something real, like a frame job that could not be beaten in court (as it was in The Fugitive) or a known societal prejudice against people with powers (as with the X-Men), not just the hero's general paranoia of authority.
It certainly doesn't help that there's plenty of examples of "the hero with bizarre powers" going public and it working out just fine. The Fantastic Four never hid what they could do and they're the best loved heroes within the Marvel Universe. (The new) Blue Beetle was terrified of the alien weapon welded to his spine, so in issue 15 he went to S.T.A.R. Labs for tests and still got to go home to fight dark gods and alien bounty hunters (and got to meet Superman for his troubles). And in the surprisingly fun Chuck, the C.I.A. and the N.S.A. know about the secrets in Chuck's brain before Chuck does, but Chuck's still working in "Buy More" in episode 2, only with two agents watching his back and trying to help him adjust to his life.
In short, if the hero refuses to ask for help because he is afraid that "they" will get him if he does, he comes across as cynical, paranoid, and in many cases, just plain dumb. On the other hand, if your hero does seek aid, and discovers that it's dangerous to do so, well then, you've done some world building, established a villain, and developed your hero all in one fell swoop! Good job!
Or if your hero has a reason to hide her powers other than paranoia... but that's a post for another time.