That message can pop up if you're doing a lot of things on the site, one right after the other. It doesn't mean you're doing anything wrong, though. Sometimes if a user has a lot of activity in a small amount of time, it means they are doing something spammy, like voting on reviews without reading them, posting nonsensical comments on the forum, etc. But it can also appear when you're just doing something quickly, like adding products to widgets, which doesn't take much time per product.
When you see this message, you might not be able to grab more products (or post comments, rate reviews, etc.) for 5-10 minutes. Please be patient and consider grabbing products a little more slowly next time. I hope this helps.