Nearly everyone I’m friends with today that I met through the fan base happened last year during The Cab Day, which is again happening this year - Tumblr here, and further information here.
Aside from that, Cab fans aren’t hard to find! You can look at who frequently is replying to the band members on Twitter, or look through “the cab” tag on Tumblr to see who posts things about the band. You could also scroll through the profiles on WATSS if you’d like.