You have domain users granted login to the box? With what rights? If so, remove it and set up appropriate windows groups and set their permissions to just what the people need.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
We walk in the dark places no others will enter
We stand on the bridge and no one may pass