yahoo did this to me. Verifying employment is one thing (I guess...), but their background check thing wanted exact salaries too, and permission to ask HR at all my previous employers.

Is this common? I've worked for small companies so haven't run into anything like this elsewhere. Except for one asshole that wanted to do a reference check two weeks after I started work (!!!) (he offered me a job at the end of the interview with a 24 hour time limit and had me start 3 days later; I had already left the previous employer so it suited me well enough at the time), and was unhappy when I told him what he could do with himself.