This is what EvenBalance (PunkBuster) says about this...
Integrity Violations:
When PunkBuster is unable to verify that a player's gaming environment is functioning properly and/or has not been alterred, an Integrity violation is raised. This also involves the detection of modified game or PunkBuster files. These violation numbers are between 10000 and 29999.
I normally have not been doing anything with these on both of my servers that I have. I have sent EvenBalance an email asking for the full definition for this type of ban to get a better idea as to what is really happening.