This is pretty scary! To suddenly lose one's coins to seizure by an over-zealous exchange simply due to the history of those coins.
It’s scary indeed. What’s even scarier is that unless you have a freshly mined BTC, if you get to have one with a very long history you have no idea how far back they go to check it. It could be 100 transactions. It could be the last 365 days, who knows? You’re just sitting there waiting for your deposit to be confirmed while some random company nobody’s heard of is looking at a history that often doesn’t even belong to you, attributes it to your name and punishes you for it.