In Scrabble, What is the big deal with playing with etched in tiles?
Apparently there is enough of a concern, because according to the latest tournament rules:


  Tiles that can be distinguished by feel are not permitted, except as deemed appropriate by the Director for players who are blind.


In addition, to keep players from swapping tiles with adjacent games:


  Adjacent games should not use identical tiles.


My finger sensitivity isn't good enough to tell tiles apart, but I'm more than certain that people with better-than-normal finger sensitivity could easilty tell tiles apart.