Stealing is just part of sports: stealing bases, stealing the basketball, stealing the puck, stealing a soccer ball, intercepting a football...
In baseball, there's always subterfuge. Base-stealing helps the offense, and a smart defense seeks to prevent it by being prepared and knowing when attempts may occur. So players and coaches try to steal signs for stealing, as well as strategies like bunts and hit-and-runs. They watch sequences of hand signals, look for repeated patterns, try to crack codes.
The offense tries the same, studying batteries, as well as managers and coaches in dugouts (and even middle infielders opening and closing their mouths before every pitch). Of course such schemes and maneuvering include studying video, before and after games -- and during, once it became available. They're not allowed eye-in-the-sky coaches stationed above the action in press boxes like in football, but they'll take what they can get.
Most of us here are Red Sox fans, but let's be honest: do any of us really think there was just one rogue video guy breaking unrealistic "rules"? The lack of uproar around the MLB regarding Manfred's Boston report shows nobody really cares, and for a reason...
But when a cocky player like Bregman tweets braggadocio, pimps HRs and carries his bat to first base, people want to take him and his mates down.