I-9 Documentation

I'm trying to assess all the pros and cons of keeping photocopies of the supporting documentation (drivers licenses, SS cards, etc.) with the I-9s.
Anyone here have any strong feelings about that one way or another?
Anyone here have any strong feelings about that one way or another?
Comments
We had an audit of our I-9's, I do not keep copies of the documentation and the auditors had no problem with that. Why make more work for yourself?