In larger communities you often can find the problem, that there a lots of nice profiles. When searching for something special you can find perfect people - but your disappointed, when you find out, that their last login is years ago...

I can think of a possibility to deactivate profiles for example 30 days after the last login. The profile still remains in the database, but isn't shown in lists.

When the user appears again, he should automatically reactivated again.

It seems to me, that this would only need an filter based upon the "last online"-db-entry, but with the opportunity to make an automatic subtraktion: Actual Time - Last Online Time < x Days.