According to Joseph Steinberg, CEO of SecureMySocial, certain area codes can tip off potential victims that something is amiss. In the past, criminals used to hide behind "900 numbers" that racked up high charges, but the public quickly caught on.Then scammers tried a new approach. Many schemes soon featured the numbers 809, an international area code from the Caribbean that appeared to originate in the United States. As familiarity with that ruse also increased, crooks have since moved on to other islands that still fall under the +1 country code. "Criminals have been known to use caller IDs with the area code 473, which appears to be domestic, but is actually the area code for the island of Grenada," he wrote. According to AARP, taking calls from any of those foreign countries can cost $5 a minute or more. The bot or person behind it can also persuade listeners to spend money on sketchy timeshares or cruises. In other schemes, people pretend they need help or money because they're in danger. Steinberg advises never returning a missed call from an unknown number — if it's for real, the person can send a text or leave a voicemail. "Remember that it's unlikely that someone you do not know — who is in distress at a location with which you are not familiar — would dial a random number in another country and ask you to help them," he says. "They would call the police."