When I started geocaching, I was very curious about all these people that were doing it. I didn't go to my first event until a few months in, so all I saw was the nickname and the find counts. Bigguy in Texas was notable then because she (not he) had caches everyplace. And HiDude_98 was also noticeable, mainly because of the number of finds. After meeting a few people, I realized that there were others that geocached that I knew for other reasons, not because of geocaching. And of course, after you meet these people, you become geo-friends, and start caching together.
When I finally started hiding, I started off mainly doing puzzle caches. In central Texas, that means I see mostly the same names over and over on the logs: HiDude_98, Buckandi, DrPflug, and SoaringEagle, for example. Some others show up a little less often, like Racer57, Czechsun, MSASO or winkys. So when I see a name I don't recognize signing the log, I get curious? nosy? and check out the profile to see if they are local, or visiting from out of town, what kind of caches they seem to like, where they've cached, and more.
I've also been goodnaturedly accused of stalking one of my geo-friends. But it's pretty easy to do, if you know their goal, and you can see their stats, you can pretty much guess if they're going caching that day. Just by looking at the profile, you can see what caches they've found, and where they've been. With the new dashboard, it's even easier to see what others are up to.
For this puzzle, you'll need to do a little virtual stalking. The local cachers aren't part of the solution. Instead, you may have to wander around the United States and even internationally. You'll need to figure out how ChrisEMT1 and CacheKeehl and "Zekester & Simon" can help you. It sounds like a scary name, but LestISmiteThee will also be a help in solving the puzzle. alfieo, TeamSweom, and Bicardi151 will be helpful to you as well.
It's always interesting to hear about how the geo-nicknames came about. Some are pretty easy to guess, like those that include their college mascots. Others might reflect their caching history. And some just get locked in because they can't think of anything else when signing up.
I don't really know where some of these came from, but there are probably some interesting stories. You can check out names like YBNORMAL@54 and Scuba_Steve_Squad and Nomex. 6Lindseys would be a big help for those alpha numeric cacher name challenges, if the challenges were still around. Sternenkletterin and Victoriousviljoens are international cachers. And finally, SocksAndAmanda and casiswarya will round out the last group.
You don't really need to contact the cachers, as everything you need can be found by stalking their profile. Contacting these cachers won't really help since they don't know how the puzzle is constructed. You'll have to figure out that yourself.
Have fun with the virtual stalking!
You can validate your puzzle solution with certitude.