Open wi-fi Prisoner's Dilemma

Whether to leave your home wireless access point open or password-protected is precisely a Prisoner's Dilemma.

The main worry people have about leaving their Wi-fi open is that someone else might use it for bad internet activities for which you may be blamed. (There is also the Firewall effect, but that can be solved by other technical means, like network monitoring, firewalls on computers themselves, and VPNs.) (Quality of Service may be used to give packets to the Wifi you're paying for higher priority than a freeloader next door, while still keeping your network open.)

If everyone left their wireless open (everyone "Cooperates"), then everyone would benefit greatly by various network effects. Everything, especially small mobile devices, in urban neighborhoods, would have a high likelihood of being able to access the internet. Cell phone companies' monopolistic practices would be curtailed. It might become possible to improve how credit card transactions work. With overlapping access points, it becomes possible to set up mesh networking to route around internet failures or censorship. (I sometimes wonder whether public information campaigns to get people to secure their wireless access points actually have a hidden agenda to prevent some of these benefits.)

If everyone left their wireless open, the legal defense that some alleged internet activity was not you is much more plausible, especially if there are frequent incidents to other access points.

However, if everyone except you left their wireless open, (you decide to "Defect") then you would still enjoy the benefits listed above of wifi everywhere, but you yourself would enjoy the additional benefit of less worry that someone might do something bad on your internet. But when everyone thinks this way, it leads to everyone closing their network, which we see nowadays and a globally less desirable outcome, just like in Prisoner's Dilemma.