Is it a happening trend today? Most people will say yes. That's what the x-generation is into. You may have them as a feature on Mobile phone, Iphone,Ipad etc as a build in feature. Its like you have to have it. You may have people with the same views,opinions or just friends. Some just like to share photos of their families & friends having a good time. While others block out some people as they feel he/she may be giving negative remarks. May it be birthday's , anniversaries you can fiind well wishers greeting you on any occassion. Of course social networking also has it negative side. A stranger can collect information about you & your friend circle. There are adult snaps which others may find it offensive. There are some who would like to add you as a friend but not more than that. The logic behind social networking is to be intouch with your friends, maybe school,college or work. It can also be a distant relation or someone you haven't seen for years. It also helps you to make freinds with people from different countries.