There are a few scams that happen in-person (the fake utility worker being one of the most common), but the majority rely on some sort of communications technology.
This gives the people running the schemes the advantages of a physical buffer (less likely to be identified, arrested or punched), global reach (not limited to immediate surroundings), and scalability (the ability to scam hundreds of people simultaneously, instead of one at a time).
According to FTC statistics, the telephone was the contact method for 69% of scams reported to the agency in 2018. By comparison, in 2008 phone calls only accounted for 7% of that total, with email comprising the bulk of scams (52%). If it seems like you’re getting more and more fraudulent phone calls over the past few years, you are.
There are ways to spot a fraudulent phone call once you’ve picked up, and one easy way of ending one (hang up without saying anything), but it may time to just let calls go to voicemail unless you recognize the number. If the call was legitimate, they will leave a message.
Of course, there are robocall schemes that use a random local phone number, then dial every number with the same initial six digits. If you do not recognize the number, let it go to voicemail. If the caller doesn’t leave a message, or if it’s a pre-recorded pitch instead of a live person, there is no need to respond. Delete the message and go on with your day.
If you do recognize the number, go ahead and answer. While you can’t trust caller ID, the chances that a scammer is “borrowing” the phone number of a friend or family member is extraordinarily low. Even if it does happen, you will know right away. You’re not going to mistake a friend for a prerecorded “press 1 to lower your rate” robocall.
If you’re ignoring the phone, you might end up with a list of callers who did not leave a message. Do not call them back. Most likely the caller ID information is fake, so all you will be doing is harassing an innocent person. If the number turns out to not be phony, you’ll end up talking to a scammer who now knows your number is good, and that you might be an easy mark worth pursuing. This could lead to even more fraudulent phone calls, and nobody needs that. We all get enough calls as it is.