I was once a newbie and I am not sure about what OP is saying because those who send PM are not high rank members, because they won't want to risk it, if they get exposed by the newbie they can get a red tag.
A newbie posted today in the Reputation board about how he received a from an old member offering to sell him merits to rank up to Junior membership:
https://bitcointalk.org/index.php?topic=5579730.msg66687004#msg66687004The forum account is a confirmed account seller and already tagged but expect newbies might not be aware about the trust system and accept the offer. Note that some old members with red tags have also some green tags that might give him some kind of credibility.
The only way to fight those scammers is to never hesitate to report to mods. Unfortunetly most of newbie accounts have no clue about this feature in their profiles.
This issue of old members sending a message to newbies for wrong business deals has been happening in the forum that was the main reason I created This thread in this board so newbies will be aware of what is happening in the forum, the link thread you posted is an evidence that old members usually PM newbies for wrong business, the account that PM the newbie is already an account known for such in the forum, some newbies will fall for all this guys because they are new in the forum and won’t understand some things that is actually going on in the forum.
You are right the only way is for newbies to report any PM they find suspicious to Mod, and you are still right most newbies don’t know how to report to mod too well I think I will create a thread about that so I can teach those that don’t know.