Sorry Op, I did not actually understand the story fully.
According to the story above, Alex is only in contact stage with the alleged or to-be partners. What really happened, did he disclose his private details at the course of the meeting?
Could it be that they hosted the meeting with tools like TeamViewer and he gave them unrestricted access to his computer?
Same question that was boiling in my mind while reading the post but glad Coyster made some enlighten explanation. The question now is whether we are to avoid joining any form of conversation through links or we should be the one to host the meeting in a case like this.
Scammers are doing everything possible to be a step ahead of us using incredible strategies and sophisticated tools. The more inform we become, the more they develop new methods. Crypto seems to be the new oil money and becomes their target.