Some people join social network not to find life partner.
Some join for experience. Some join for the purpose of learning.
Some join to get some stories for their journals/articles.
People join social network for many reasons.
For most people, girls especially, those who r not interested in finding life partner on the net cause of many reasons, probably they do not trust those with mysterious identity.
In order to do that, so not to have anyone bothering her/him with all the naughty stuff, they pretend to be married.
Where else for those who are probably a little naughty or perhaps out of curriousity if they are still having that power of good looking or power of seducing others with their words, and expirience. They prefer not to dispose their status or stated as single <- dangerous lol