I have come across accounts(both group and personal account) on telegram with very much identical name with one from the forum and not just that it's a coincidence they do portray themselves to be the authentic person from bitcointalk
Before engaging in any transaction or deal with someone on telegram on cryptocurrency related matters, it's important to make sure that person has a bitcointalk account, and you must verify if such individual is actually who they claim to be, requesting a pm is a good idea.
And if you must then go ahead with the transaction, it's safer to do so with an escrow service, not just any, but the comprehensive list of bitcointalk escrow service, you can find it in this link:
https://bitcointalk.org/index.php?topic=2439910.0don't know if such measures has been thought about on the forum like users with high trust getting a symbol or mark attached to their account or their alts
I think the trust system is sufficient for this, if a user you attempt to deal with has negative trust, that's a symbol that brandishes a red flag already, but if it's positive trusts, then to an extent, such user can be trusted.
As for their alts, most high ranked members openly declare their alts, as well as add links to it in their main account, to avoid impersonation.
Good post you got there,i do hope newbies adhere to it, even if i doubt they will