Pinterest question

[ratcreature]

Does Pinterest somehow add boards to what you follow when you're not looking via some algorithm or something like that? Whenever I've been away from the site for a while and then check back there somehow are a ton of pins on my dash from boards and people I don't remember following (at least I'm fairly sure about that, though they often vaguely overlap with previous interests).

And is there a way to turn this behavior off?