&gt; &quot;Unlicensed&quot; isn&#x27;t really &quot;unlicensed&quot;, as much as specifically licensed for anyone to do with as they please.<p>One does not need a license to operate a radio in the WiFi bands, so that spectrum is unlicensed. However, it is not <i>unregulated</i>. :)<p>&gt; Anecdotes: 1: on London Underground, my phone authenticates using the SIM somehow...<p>That might be EAP-SIM [0].<p>EAP (and WPA2-EAP) is <i>really</i> cool. I <i>really</i> wish that MSFT would configure their WiFi supplicants to not care if the key of the PEAP or TTLS server they&#x27;re talking to is signed by an unknown CA. This would let coffee shop owners deploy encrypted but password-less WiFi and shut down a whole class of attacks. [1]<p>[0] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Extensible_Authentication_Protocol#EAP-SIM" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Extensible_Authentication_Prot...</a><p>[1] Seriously, MSFT <i>obviously</i> designed their WPA2-EAP GUIs <i>only</i> for use in an enterprise environment. There&#x27;s <i>no</i> way for a Windows user to connect to a WPA2-EAP network that uses PEAP or TTLS with a cert from an unknown CA by just clicking on the network in the network browser and punching in some credentials. You <i>must</i> manually configure the network, then uncheck a checkbox buried beneath a couple of menus. What&#x27;s more, the error you get if you don&#x27;t do this is <i>entirely</i> unhelpful. :&#x2F; In contrast, Apple&#x27;s GUI for this is actually useful: &quot;This cert is unknown. You want to trust it for this WiFi network?&quot;. Say yes and off you go!