Why hasn't anybody figured out to put a reasonable time limit on each device Mac address? 1 hour since you first log in should be enough to satisfy 90% of customers and discourage the 10% hogging seats. Its like saying - you are limited to 5 refills and being able to enforce it discretely. Who would object to that other than those taking advantage?
I think the reason is because that really didn't work for some reason. Starbucks experimented that idea for a while. (I think it was something like 3 hours for buying a something using registered card, and that then they decided to open it up...)
My personal opinion about MAC address filtering though, if they become the norm, everyone will start using a piece of software that changes MAC address periodically... (As it's already trivial to change your MAC address...)
