In theory, getting free stuff sounds great. But what if it’s stuff you don’t particularly need or want, and it just keeps coming?

A new scam called “brushing” involves exactly that. Reports are growing of people receiving shipments from Amazon of items they didn’t order, sometimes the same item over and over, with no real mechanism available to stop the unwanted deliveries.

What exactly are they up to?

Shady sellers are creating fake Amazon accounts, then buying their own products and shipping them to random addresses. They then post five-star reviews of their own products. Since the system shows the item was actually bought by the reviewer, this review appears as a “Verified Purchase,” which makes the review more prominent, and the great average customer rating boosts the item’s rank in Amazon’s search function. The ultimate goal is to sell sub-par products to consumers tricked by the high average product rating.

What should you do if unordered shipments start showing up?

First, contact Amazon to let them know you’re getting them. Amazon will attempt to figure out who is behind the scam and delete the seller.

For the most part, Amazon has been telling people to either keep, donate or discard the actual items shipped. That part is up to you.

So far it doesn’t appear that the people receiving the shipments have had their accounts compromised. However, if you start getting things you didn’t order, go ahead and change your Amazon password (which you should do now and then anyway). The addresses used for shipping seem to be chosen at random, though there may be a link between previous purchases from overseas sellers using the Amazon platform. When you’re shopping on Amazon, pay attention to the “sold by,” “fulfilled by” and “ships from” information, and favor domestic sellers (or Amazon itself) and orders that are fulfilled by Amazon.

Fakespot.com is a good resource for checking out products on Amazon for fake reviews (it also works with Yelp, TripAdvisor and the Apple App Store). It’s not foolproof, but it can at least give some insight as to how trustworthy an item’s reviews are. All you have to do is paste the URL of the Amazon item into Fakespot, and it will give a letter grade and a percentage of high-quality reviews as determined by the site’s algorithm. Anything with less than 80% high-quality reviews, I would avoid. Pay attention to the negative reviews, too, to see what customers who didn’t like the product are saying. If fewer people buy items with tons of fake five-star reviews, the motivation for the brushing scam might dry up a little.