It’s pretty common for businesses of all sizes to sell products on sites like Amazon or eBay.

So imagine one day receiving a “take-down notice” informing you that the site is taking down your listings because another party has demanded it under a federal law called the Digital Millennium Copyright Act (“DMCA”). According to the notice, the other party says your goods infringe its copyrights.

If you ever receive such a notice, be sure to look carefully into the matter. That’s because it’s become more common for these demands to have no valid copyright infringement claim to back them. Or worse yet, sometimes the demander doesn’t own any copyrights at all.

Based on Google’s Transparency Report, approximately 40 percent of take-down demands stem from invalid copyright claims. And some requests don’t even come from real people. They come from automated Internet bots developed by people who want to get money from businesses to stop the take-down.

Meanwhile, under the federal law companies like Amazon and eBay aren’t on the hook for deciding whether the demands are fair. They’re only required to make sure the notice includes certain required information and to send it along to the business in question. After the demand is made, the provider will delist your goods and let you know it has done so.

The good news for businesses is that the law gives you a useful way to get your products back online. What you have to do is send the provider a “counter notice,” indicating that you have a good faith belief that your items were taken down “as a result of mistake or misidentification.”

The provider is then required to send your counter notice to the demander saying that your products will be re-listed within 10 days, unless he or she has filed suit against you to bar you from selling the items on the site. If no suit has been filed, the site must put your items back up within 10-14 days of receiving the counter notice.