anyone ever tried back counting blackjack or does security catch you instantly

I’ve always stuck to machines and avoided table games mostly, but I keep hearing about this back counting stuff with blackjack. The idea sounds tempting - just hang around the table, count when it gets good, then jump in for a few hands. I can’t tell if this is total movie nonsense or if it actually works in real life. I’ve seen security get a little tense when folks lurk behind the seats for too long, but never seen anyone outright kicked for just watching.

It feels like you’d have to be slick about it. I’ve heard stories where pit bosses have eagle eyes for this kind of thing. Curious if anyone has actually pulled it off or if you just end up with some grumpy dealer staring you down.