As the old saying goes: if you can’t beat ’em, join ’em. That’s a mindset that’s been fully embraced by Riley Walz, a 23-year-old “tech prankster” who runs a popular account on X-formerly-Twitter.

Waymo’s self-driving vehicles have helped turn robotaxi services from tech demo to daily reality, but like any connected system, these days that same openness invites a bit of mischief, and the ...