[faizanaziz]

Please visit the website. There I explain what the problem is.

In summary, since the user does not pay them and they need to be profitable there only option is to sell the resource they have. That is the users content. But selling really personal things like photos will be a huge deal and the users will get really upset. So instead they term it as 'sub liscence your photos / personal information' to third parties. Which basically means that advertisers can use your photos / personal information.