Are there any articles discussing the legality or cons/pros of Social Network sharing sites?

[TuTu]

I am writing a paper for class on the subject of such sites as Like-Ex and SocialMediaExplode which allow members to post links to thier own Social Media/Network pages (i.e. fb, yt, instagram, twitter, tumblr, etc) and share with other members by way of a point system. You watch, like, subscribe to other members links to get points so that others can do the same for the links you post.

I think it is a very interesting topic and quite different from paid advertising (such as google AdSense) and so called "buying" websites, where you may pay for a certain number of views/likes/followers/comments but they may come from bots/spam/etc.

I would like to know if there are any existing materials about this subject.

Thank you and five stars to the answer!

[Aj]

Yes, there are many such articles. Here are just two links.
http://www2.readingeagle.com/article.aspx?id=412755
http://ultratechtalk.com/pros-and-cons-o...ing-sites/