Maybe you've gotten one of these already.
Your phone rings, and on the other end is a friendly man or a woman who introduced themselves then asks something along the lines of "can you hear me okay?"
The hope is that you answer with "yes," because in truth this is just a recording made to sound realistic in order to prompt you into being polite, but in truth they are recording you, and they can then take your "yes" and edit it into you agreeing to something else, usually a large purchase of some kind.
From the Daily Dot:
The Better Business Bureau reports that for the last few days of January, more than half of its Scam Tracker reports have been about this particular issue, which is rampant in both the U.S. and Canada. In many cases, the “Can you hear me?” comes right at the beginning of the call (again, before you may even realize it isn’t actually a human being calling). The BBB recommends not responding and hanging up ASAP if you’re asked “Can you hear me?” or a similar question.
For those of you have received these calls and have answered yes, the good news is that there has yet to be any actual reported attempt at collecting money, or charges. The debunking website Snopes has a list of reports about the scam calls, and each case is said to have cost the scammed zero dollars. Regardless, authorities are issuing warnings to be more safe than sorry.