Make an error or two (vs. perfect counting strategy), and they'll let you keep going, because long-term they'll still have an edge. Count/play perfectly and you'll get backed off or 86'ed.
It's well known that when you're counting cards, there is always a swing to when the player has an advantage. If you're upping your bets when you have the advantage, and then lowering them when the house has the advantage, they'll usually stop you from playing at the blackjack tables and either ask you to leave, or tell you to play something else where they have the advantage, like slots.
I assume casinos use infinite shoes now so it's not even an issue?
Obviously errors aren't sustainable, since the edge is so small, but I wonder if it might be possible to open with an error so you can stick around a little longer before someone checks back in and bars you. More broadly - are counters these days trying not to get noticed, or trying not to get banned?
It really depends on what type of game you are trying to cheat if you are avoiding detection or avoiding a ban. With slot machines, if they think you are up to any mischief, you will face legal issues. As for cards, the casino is going to be aware of your activities if they have any inkling of things like card counting. The dealers know what to look for and you will be watched. The casino is just trying to make sure you don't take too much from them but they also want you to keep winning, it makes others around you think they have a chance too. Make a few mistakes here and there and you delay the moment when they tell you to get lost for the night. You will get noticed so your only option is to just avoid getting banned.