[beagle3]

Do you know which jurisdictions have a precedent of ToS being considered a contract?

Being a one-sided, no negotiation and with no "meeting of minds", most European jurisdictions won't consider this a contract -- facebook can kick any user out, but it is unlikely they could recover damages from anyone (or have standing). At least that's my impression -- though US courts, especially in states that have UCITA or similar, are more likely to consider this a contract.

edit: I've found two jurisdictions, and both of them require proof of actual economic harm for standing (among many other things). I'll wait for more specific details about Facebook's approache.....

[Reelin]

In the US at least, yes, but it varies based on the specific situation. (https://law.stackexchange.com/questions/13549/)