let's think some of them are directly spammers and the rest directly "stupids?", silly or something alike?. i go on the streets every day with my own face. so, why not here? about personal info , i just writte up to what i want to be known publicly as a public introduction, just like when on a social circumstance whatsoever.

Hello Ravi, Either protecting their own identity from scammers as Jura said or hiding their identity for different reasons ,such as acting silly online or on any program like that one here as well or to pretend to be someone else . There are many psychological reasons to it .

I think that a lot of people are afraid of scammers or they want to present themselves to the world in a perfect manner. That's why we see so many film star photos here.

Answer is simple - because there is virtual reality