Though details were somewhat sketchy, music site Last.fm acknowledged a leak of some user passwords in mid-July. But if there's such a thing as good timing for a password breach, this was probably it. The Last.fm incident was sandwiched among multiple higher-profile breaches. Aside from occurring within short succession of the aforementioned breaches, with around 420,000 passwords leaked, Last.fm pales in comparison, shockingly, to the hacks next up on our list. The company's advice? Okay, everybody now, in unison. "Change your password."