Programming :: Identify Users Who Forbidden Files In Home Directory

I have to create a script to identify those users who have un-sanctioned (forbidden) files in their home directory. I tried something like this (this is a try and I need some opinions):

Code: #!/bin/bash
user_belongs() {
if `groups $var1 | grep $var2`
then
return 0 else
return 1
fi
} .....