He's always been obsessed with one of the most generic computer culture related things that exist for some reason, like some nerd who has to get their exact character name in every video game they play but with billions of dollars to do it.
It's also been used as a symbol of the Russian invasion (since during the initial attack, the Russians used Z, V, and O as markings on their vehicles. Fortunately, O never seemed to catch on at all, probably cause it's too generic a shape.) You saw it sometimes in Russian propaganda alongside the Z, especially towards the beginning of the war. But it seems like it's been mostly phased out in favor of focusing on Z in the last few months.
And yes, can't believe I forgot about Q! Although that's probably a good thing, because it hopefully means QAnon's peaked and is starting to fade? Finger crossing intensifies