That's a great question! It's surprisingly common for bins to get stolen or blown over. Here are a few methods I and my neighbors use to keep them anchored:
For a permanent solution, ground anchors or screws are very effective. You drill a heavy-duty anchor into a concrete pad or directly into the ground (if it's compacted). Then, you use a sturdy cable or lock to tether the bin's handle or a reinforced point on its body to the anchor. It's secure but requires some installation.
A simpler, non-permanent method is using weighted bases. You can purchase specially designed weighted plates that sit inside the bottom of the bin, or create your own by placing a bag of sand or gravel in the bottom before the liner. This lowers the center of gravity and makes it much harder to tip or carry away.
Locking systems are another good option. Some bins have built-in lockable lids, but to prevent the whole bin from being taken, you can use a bin lock kit. These typically involve a strap or bar that loops through the bin's handles and locks to a fixed point, like a fence post or wall anchor.
Finally, strategic placement helps. Keeping your bins in a locked side yard, garage, or chained together in a pair makes them a less tempting and more cumbersome target.
The best choice really depends on your local problem (theft vs. wind) and your property setup. A combination of weight and a simple tether often does the trick!