At least it appears to be something that gets triggered. In theory, if a node is not under attack or heavy usage, this isn’t a consideration. Doesn’t seem to be a perfect solution as it still slows the traffic of legitimate users in the event of an attack. I don’t know the full details, but in the worse case it makes it easier to semi-DoS, maybe not by fully making a node unresponsive, but by making the service so painfully slow that users may give up on it.

There are several reserved names in Windows. This is for backwards compatibility with mostly DOS programs. On your desktop, try and create a folder named “con”, and Windows should flat-out refuse. (Same thing for “prn”, “aux” and “nul”)