CaptainWoody - They can legally just ask for the info from your employer if they want.
Your current or former employer does not have to divulge unless it is requested from a legal entity or the government. Most employers will not divulge.
There are things that legally can be asked when checking current or former employers, income is one. They cannot however ask "what kind of employee" a person is/was or the reason they are no longer employed (if relevant). They legally do not have to divulge anything except if you are currently employed or the to/from dates of when you were employed. This may vary state to state, I'm not sure.
They can ask what kind of employee a person was or why they were terminated. There is no law against it. Employers don't answer because there is a risk for a defamation suit if they answer with an untruthful response. Thus, most employers opt to reduce the risk of suit by having a policy of not answering. But they could if they wanted to.
I think this is correct.
I was going by when I was a supervisor years ago in a different field then I am now. It was probably company policy to not divulge anything, that's why I was told I could not say anything other than employment history.
I would get calls asking about certain people that were total pieces of shit and had been written up multiple times before tey were fired...all I could say was, they were employed from this date to this date.
I did get 1 or 2 calls for people that never worked there ever and I told them I had no record of this person ever working at this company. That was strange.
So even if you were fired and a bad employee I think most places aren't going to say jack shit, for one, you aren't their problem anymore and two, it's not worth the risk of a defamation lawsuit.