Breaking an agreement with your employer is a civil act, at least in the US. "Confidential" information is a pretty broad designation as well, so things like in

Breaking an agreement with your employer is a civil act, at least in the US. "Confidential" information is a pretty broad designation as well, so things like insider trading and trade secrets can be a criminal act but other "confidential information" your company deems so might only be a civil violation or perhaps not even that if it's not covered by signed contracts.