A friend is on misdeameanor probation and a form she needs to fill out requests bank acct. info. Is this legal and what do they use this imfo for?

Yes the probation department has the right to ask and know everything about them. Most likely it is for them to keep track of how much money they have ( do they have fines or other money to pay the court) What is the crime they are on probation for ?

And why are they having a problem telling them, Are they hiding something ?

They don't have to give it, and they can merely just go to jail instead.

Hello P:

A citizen who hasn't been convicted of a crime in a court of law, HAS rights against searches such as you describe. However, a person who is a convicted criminal who is serving a sentence does NOT have the same rights as one who has NOT been convicted.

excon