Well, the concept exists, at least:
https://bravenewcoin.com/news/the-bitcoin-big-bang-tracking-tainted-bitcoins/
...so I wouldn't be surprised if exchanges are availing of blockchain analysis services to filter them out. I've never heard of such a specific case happening, but we know authorities have the means of tracking criminal activity through the blockchain.
I found this, but I have no idea if it's legitimate:
https://steemit.com/bitcoin/@gtacx/don-t-use-coinbase-coinbase-are-coin-nazis