This kind of map actually needs some minimal classification. There are actually flavors between free and open wifi.<p>For instance, how would you categorize a wifi in an airport which needs you to fill a random form&#x2F;survey (not paying anything) to access the Internet? Same question if it is then limited to something like 10 minutes (and you then need to pay, or just trick on your macaddr&#x2F;dhcpname&#x2F;...)? In these case, you can actually access the Internet for free, but they are extremely annoying.<p>Note: these kind of wireless network are actually very common in some places