The FMA has been warning consumers about boiler room scams, a worthy task. Apparently there has been a big increase in the number of complaints - and I guess that the number that actually complain is much smaller than the number that have been ripped off.
These scammers, confidence tricksters, or common thieves, will call you - at home, on your mobile, or contact you by email. They range from the laughably amateur, to the scarily slick. Get across it, read up a bit, have a chat to your family (including teenage kids, anyone that might actually answer the phone) and get hard: just hang up. They may call back. Hang up again!
Meanwhile, watch this guy, who gets high quality entertainment out of scams.