He's not gone. He has been harassing me on telegram and messaging past clients whom I ran campaigns for. I guess he thinks he's doing something, but he's not.
So, how is he supposed to get the addresses of your past clients to send them PMs via Telegram? I say this because apparently
it is believed that 
I have done the same thing and I would not know how to get the addresses of your past clients or those of another manager. I'd like to know, lest I get the urge to actually send PMs , lol.
If you check yahoo's (for example) profile page and click on "Show the last topics started by this person." you will easily see a list of all the (topics) campaigns he opened. Almost as a rule, in each of these threads, there are all contact channels from the project and campaign owners.
I'm surprised if you asked this seriously.