You might have heard about online "phishing" scams designed to steal money from unsuspecting Web users, but now criminals are using another type of scam called "vishing" to commit the same crimes.

Last week, the Federal Trade Commission filed lawsuits against two telemarketing firms in Florida and a company claiming to sell extended automobile warranties for violating the Do Not Call registry and fraud for selling bogus warranties for between $2,000 and $3,000 a pop. Since 2007, the compan...