Remind me never to sell a Skip the Dishes insulated pizza bag ever again on FB marketplace. Most people want $30-$50 for the bag. I found it for $5 and put it up for $10. I'm not a "charge what the market will bear" guy. If I can 2x my money and get something useful into someone's hands for less than what others want, I'm okay with that deal. But, man, must have had 14 people "Is this available?" "Yes" then silence. Had one guy "yup, going to pick it up! Coming !" Finally told him "You need to come before 9 pm". "Yup coming!" 9 pm came and he didn't show up. Messaged him and told him "no sale".
Anyway, finally got a guy to go through with the deal. Lot of answering pointless messages for $5. Oi.
Had a person send me their number as an interested buyer and told me to text them. I did (first mistake), and we arranged a meetup time. Then they asked if, for their safety, they could send me a six digit code (some of you already know where this is going) that I could repeat back to them to verify myself.
I said, "absolutely!" And sure enough, I got a Google Voice verification number. lol
If you're not familiar with the scam, shady people will take your phone number and try to create a Google Voice account with it. If you provide them with the 6-digit code that Google sends you, they can "verify" that they are you, and then basically use your phone number to run scams, commit fraud, etc. It's nasty business.
I called them out, blocked them, then reported them to the marketplace website and to the FTC--though, almost certainly, they were using the phone number of another poor soul to carry this out.
I used to work as a social engineer, running phishing campaigns (ethically, with consent lol), against Fortune 1000 companies to assess their level of vulnerability. Luckily for me, I was super familiar with this, but most of the people I told about it have said, "Oh, I probably would have fallen for that...", and even I set myself up for it.
So that is why I'm posting this. Please be aware of sketchy shit like this. If someone is asking you for a verification code over SMS or email, tread with EXTREME caution. Also, it's usually pretty shady if a stranger you're already chatting with wants to move to a new platform. Not always, but if someone emails or messages you on Facebook to ask you to text them, that's a little weird. I'd had legitimate buyers/sellers do that, so it's not unheard of, but it should put you on guard.
If you buy/sell/trade online frequently, it's a good idea to use a dedicated MySudo number, VOIP number, and/or a burner phone for that.