Alert system for unique usernames

Hi,

I am looking for some kind of alert system, where i can be notified when and if people log into my server. Preferably mobile based. Been having issues with my children's sever with a certain griefer. I dont want to have to block the IP adress, because of other siblings that use the server. If anyone knows of a plugin that will do this, it would be hugely thanked! I have been searching for a while now, and cannot find one that works for my need!

 

I see your request, but what about just banning the griefer's username?

 

My server unfortunately runns in Offline mode, many of the users are familys and therfore cannot afford buying two or more accouts for their children. He is a smart little bastard, and found out about logging in with false ID's. If i can track users by IP login, ill be able to catch him faster before he has a chanse to cause me a headacke!

 

Prepare to be accosted.

 

It's been 15 minutes already - LaxWasHere must be asleep!

 

Locked. Offline mode servers are inherently insecure and unsupportable.