Spam, wonderful spam (bloody vikings!)
Not really, but neither is it an open book. Obviously one should have most beliefs in line with some 'branch' or sect from within Hinduism. Anyone can say 'I'm a Hindu' but id that doesn't match with some actions, or beliefs pertaining to Hinduism, nobody's gong to believe it.
Sure, people call themselves all sorts of things! I don't currently describe myself as a Hindu, though obviously I have a strong interest in it.