The paper is very light on details. I'm a little surprised MIT published this actually. It doesn't present anything new, and hinges on vulnerabilities since fix

The paper is very light on details. I'm a little surprised MIT published this actually. It doesn't present anything new, and hinges on vulnerabilities since fixed to say that there are definitely new ones. Snooping on friends by looking at when they are online is interesting, but something known for a while and circumventable by just changing who can see your online status (I think it's people on your contact list by default). If you're expecting a security vulnerability, this isn't the paper to find one in (not that rolling your crypto is a good idea)