Sure you can, and that behaviour is rather mainstream by now, but it wasn't long ago it was considered very egoistical. Every time you install an app and you a

Sure you can, and that behaviour is rather mainstream by now, but it wasn't long ago it was considered very egoistical. Every time you install an app and you agree to upload your contact list to someone? That data was not yours to share. Every time you put a little tracking script on your web page in exchange for traffic graphs it is your customers data you sell. Not your. Every time you email me everything I write ends up indexed under my email address, to be sold to another company and cross referenced. I didn't agree to this. That like button you put up that reports all your visitors behaviours? Not your data.