I would agree. If you cease use and end the agreement then they should stop. If they continue then they should be liable.

“When you delete content, it's no longer visible to other users; however, it may continue to exist elsewhere on our systems”

This is from FB’s terms and conditions, so I guess they can still keep the data.

If you agree to any other website’s terms and conditions saying “any third party can track you”, you have again given permission.

The problem with this interpretation is that valid contracts depend, among other things, on informed consent and on the legality of what's being required, meaning you can't trick someone into being bound to terms they never really accepted or sufficiently understood and you can't bind them to illegal terms.

In this case, most people haven't read the Facebook terms of service and it is probably unreasonable to expect everyone to not only read them, but to keep abreast of any updates. So it's a grey area. And if you pass laws and regulations around data privacy, then FB won't be able to legally impose such conditions. But as I said earlier, there isn't much inertia behind data privacy. Nobody with power wants it.

> valid contracts depend, among other things, on informed consent and on the legality of what's being required

Yes, and they also depends on power dynamics.

That's why there are a lot of restrictions on what can be written in a contract between public utilities and users. An electricity provider could strong-arm users into signing draconian contracts otherwise.

Social networks have the same negative externalities: if most of your friends move from using emails to using Facebook to communicate and you are not on it your life gets provably worse. You are cut out from a lot of your social circle.

Having walled-garden social networks is anti-competitive by design.

Unfortunately legislators turn a blind eye to this.

>Nobody with power wants it.

Or is too influenced by big technopoly lobbying dollars.

“most people haven't read the Facebook terms of service and it is probably unreasonable to expect everyone to not only read them”

I completely disagree with this thought process. If a website is asking your birthday, every like / dislike , every detail about relatives and is able to predict if you like someone even before you do .. you better know how they will use all this data.

Strictly speaking you're correct, but you're describing the should rather than the is. There are too many overly-long ToSes written in arcane legalese to do mundane things like use a website or play a game for the average person to comprehend even the fist time for everything they use, let alone keeping up with the changes and their implications.

To coin a meme: "Ain't nobody got time for that"

On the other hand consent given once does not imply giving consent forever.