The NY Times reported on the problem (More Celebs Show Up on Google Plus, but Which Ones Are Real?) of more and more celebrities showing up on Google Plus, but without a verification system in place, it is hard to tell who is real and who is moonlighting as a celeb.
The trick to verification is that the social networks don't want to hamper the process of free and simple access. Nor is it feasible to verify "by hand" the breath of companies, celebs, misc. personalities and interests that use their platforms for business and play.