I've noticed that on a lot of news sites and stuff, there is that icon that says "Share with Facebook" and sometimes even information about friends that have commented on the particular news article.
Does that mean that Facebook are not going keeping track of what I do on facebook, but also what I do on every facebook that has the "Share with Facebook" sign whether I like it or not? If so, what amount of information could they track? Just the fact that I went to that site or more specific information about me?
Same with google ads, a lot of sites have google ads - if I'm logged onto my gmail, does that mean google literally has a live web history of every site I've been to?
Is there any "blocker" apps I can download in order to prevent large companies from linking my web activities with my email or fb account?