1. I have found that this is tied to the new "local snapshot" feature of time machine, which is enabled regardless of whether or not you use TimeMachine.
System Preferences > Time Machine > Options, Deselect Create Local Snapshots, restart. Fixed the problem for me!
2. You just really don't need to question where people are getting their copies of Lion. There's no point other than to just give yourself some sort of false sense of satisfaction. People who put alpha stage software on their machines are all clearly hobbyists. Don't hate your own kind.