The concern is that having the monitoring information available is equivalent to collecting monitoring information. You are required to collect monitoring information for certain loans, but the practice is prohibited for other loans.
For CIP purposes you must verify your customer’s identity. You may do that by checking a driver’s license, among other methods. You must record the method of verifying the identity, but you are not required to keep a copy of the driver license. Keeping a copy raises the spector of a fair lending violation.
Most examiners will not cite a violation when the license is retained for CIP purposes. If you decide to keep the license, you are less likely to be challenged by an examiner if the copy is retained somewhere other than the loan file.