Virtually anyone with an email address can request money from someone with a PayPal account. That's the double-edged sword with PayPal - it's simple to set up and use for legitimate purposes, but fraudsters can count on that ease-of-use to try and perpetrate scams.
The PayPal Money Request scam has been around for a while, but occasionally we see an uptick in old tricks, so consider this PSA a friendly reminder.
Here's how it works: You receive an unsolicited email with the subject "You've got a money request." You may just delete the email out of hand, but if it is not a spoof email and originates from PayPal (obviously don't click on any links within the email), the next time you log into your PayPal account you'll see the pending money request in your account activity page.
Once you're logged into your account, the Transaction Detail page for the money request will give you two options - Send Payment | Cancel. You'll (obviously) want to cancel the transaction, and you'll want to do it sooner than later, as the money request can blend in with other PayPal transactions if you're using it frequently.
Someone wrote about this scam in 2009 about a $5 request. Commentors in 2010 said they were getting $10 requests. The screenshot below from a recent request was for $50 - chalk it up to inflation.
This type of scam is really a numbers game. Fraudsters are hoping these requests are received by people who are either naive or more likely, busy online merchants who make dozens or sometimes hundreds of PayPal transactions daily, and may unintentionally authorize a payment before realizing it wasn't attached to a legitimate transaction.
It doesn't take a high percentage of success to make this venture profitable for a scammer. And it wouldn't be pervasive if there wasn't some level of success. So remain vigilant.