I saw it already. it is the usual problem brokers working for different schlock firms, any proper audit from the SEC,Nasd would have uncovered the problem years ago.
it doesn't matter. they likely violated know your customer rules. based upon prior actions these brokers should have had their licenses revoked. the SEC as usual comes involved after the horse has left the barn,
your advice is useless. you don't even know where these Israelis are located assuming that there is an iota of truth to the OP losing 750K. furthermore you will not be even able to determine who the identity of the individual Israelis involved.