Okay, I got a notice from them. "Please note that this number shows the number of attempts to enter a code on one device within 30 days, for now. In future, we should be able to see exactly what you expect (number of devices linked to one code), however, this is yet to come. It is a feature that is still not working as planned and for now, it shows how many times a code has been entered on one device. So, if you repeat this process on a device, the number will increase, but it will still be the same device. The bottom line is, you have nothing to worry about, that your code might be used by someone else. " is what I got. That, and I thankfully won't get overcharged.