In the past, when the Miken Freaks were still legal (at least in USSSA), they had a cracking problem as well. Some of the cracks were obvious, some weren't, but you would always feel the cracks (and please keep the perverted comments to yourselves!).

You'll know there may be a problem with a bat by listening as well, even if you did inspect them in the pregame. I had one (a cheap Worth) last year, it was fine in the pregame inspection, but the second or third batter to use that same bat in the game, the bat had a funny sound to it, and sure enough, it had cracked some time during the game.