Phone scams are a booming business. By one estimate, nearly 45 of calls to cell phones this year are fraudulent, up from about 4 two years ago.br According to Business Insider, there are lots of red flags to watch for if you think you're being scammed.br First of all, don't trust your Caller ID. The IRS, Social Security, and Customs and Border Patrol won't ever call you.br Second, don't respond to any threats or deadline-driven time pressure. That's not how real investigations go.