if you post a picture of a funny nearby wifi name that's unique and been around for a few months or so, i can tell you the gps coordinates where you found it to within a few hundred feet.
if you aren't comfortable posting your approximate location, don't post the wifi name!
if you want to know how, then let me tell you about wigle
i first came across this tool while reading a fairly thrilling account of a forensic analysis trying to track down a network intruder. at one point, he gets a wifi name the perpetrator, he goes to wigle, and is able to correlate it with some other information to pin down their address and, subsequently, their identity.
wigle is a database that stores lots of network information with gps coordinates. people will walk or drive around with some network equipment (sometimes as simple as a phone running an app) that will soak in all the surrounding wifi info it can see and pin it to the gps coordinates at the time. then, they'll send it to wigle, which triangulates it to find its likely origin point and lists it in a publicly searchable database.
quick example
if i search for cohost, i can find seven entries in history: three in seattle, two in denver, two in dallas. not a very popular wifi name! here's what the search results looks like
someone in dallas set up the "COHOST" network around december 2015 using one mac address (F8:etc), then in january of 2016 changed the mac address (to D4:etc), and then took it down in march of 2017. just how precise is that mark i have selected?
pretty specific! if you see the little green dot southeast of the pin, that's where the second mac address showed up; probably the same building. now, i can go to street view, look around 2016, and see what kind of building we're looking at
ah, well, nevertheless. maybe the billboard had wifi? let me just look around a bit more...what's this?
turns out, a few years later, a couple blocks down, a business coincidentally named cohost (est 2010) opened up a storefront. prior to that they were probably operating out of a nearby space without a storefront, and had their wifi set up as their business name.
so that's a whole story, just from the wifi data. for this example i used a public business, but hopefully the specificity here drives the point home to not post unique SSIDs, especially if they are some combination of unique, persistent, and near where you live. if you see one in a hotel while traveling, yknow, that's probably fine, whatever. but definitely not places you frequent.
so is this some kind of stalker tool or what
it is not. they have a faq explaining the many purposes (education, research, journalism, fun), but there is some incredibly cool information you can only really get by having thousands of volunteers walking around soaking up network data.
for example, from their stats page we can tell that 65% of wifi networks were unencrypted in 2002, just wide open. in 2010, about half were encrypted, with 90% of the encrypted ones using the (now known to be very insecure) WEP standard. today, about 80% of wifi networks are encrypted, with 90% of those being the (secure for the time being) WPA2 standard. before i learned about wigle, i would have said that this information was permanently lost to time and impossible to know. but, poof, here it is; this is only possible by having distributed data collection and the sustained interest to maintain it.
how about this one: from another stats section: the most common "fun" SSID names (not a business name or nondescript label like 'staff' or whatever) are "FBI Surveillance Van" (66,424), "PrettyFlyForAWiFi" (64,022), "HomeSweetHome" (38,926), "FBI" (33,430), "BATCAVE" (33,382), "HOGWARTS" (32,750), and so on. you really get a sense of what kind of names everyone converges on. fbi ha ha very funny guys.
i don't like this. i don't want this
this particular database is public, but companies like google and microsoft maintain private databases to use for location data; surrounding wifi names can be a very helpful shortcut to pinning down your gps location, for example. to opt out of google's, you include _nomap in your ssid. to opt out of microsoft's, you can include _optout in the ssid1 or fill out this form. wigle respects both labels and will exclude networks with either one of them in it. or you could just name your network the most common wifi name in the world (xfinitywifi) and cloak yourself that way.
when i first learned about this i was floored since this was not in my personal threat model at all, and still nobody really talks about this. i'd like if this was more commonly known, especially among privacy-minded people.
