Like the player getting a 95-mph fastball in his ear.
Nowadays with pitch f/x and other systems they will able to tell if the umps are being unreasonably favorable or unfavorable to certain players. How many balls where called when they were really strikes or how many strikes when they were really balls depending on if you pitch or are a position player. Veterans and rookies have always been called somewhat differently, a gay rookie or veteran that comes out will be scrutinized even more.
As far as a pitcher moving someone’s feet or intentionally sticking someone, yeah that’s going to be a big bag of worms. Absolutely never throwing in to a certain guy for fear of what might be read into it if you hit him, that will certainly allow him to dive out over the plate after whatever he wants.
Freegards