TradeSatoshi has been sending payment for withrawals of  BTC with absolute minimum possible transaction fee. making sure that the transaction goes unconfirmed and better yet they even double spend on those transactions.
they have been sending trxid with  
0.25 sat/WU - 1 sat/B


just one of the proofs of them is here... you can follow the trail and find they have been doing this for almost a week now!



https://www.blockchain.com/btc/address/1APuKMiXr89n5rb9iUKqcrAZ5jiQ6SFmoo
https://www.blockchain.com/btc/address/1A5FjoJzYpY674bZtENAg4Sy5ae7MGrEMr
https://www.blockchain.com/btc/tx/7976eb6ac462d751d7495c64f2c2f5950d80fa662304630d1b6ac28e8356ae9d
https://btc.com/7976eb6ac462d751d7495c64f2c2f5950d80fa662304630d1b6ac28e8356ae9d