Bitcoin mixing is a process of taking money from one account and breaking it into hundreds or thousands of smaller transactions to transfer it to another account. BitMixer’s owners said they were shutting down the service after realizing that Bitcoin was a “transparent non-anonymous system by design”” The service’s owners are well aware that criminals used their service to launder their ill-gotten Bitcoin funds. Authorities also arrested the owner of the BTC-e Bitcoin trading platform for his involvement in laundering money from several hacked Bitcoin platforms this week.”
Source: https://www.bleepingcomputer.com/news/technology/internets-largest-bitcoin-mixer-shuts-down-realizing-bitcoin-is-not-anonymous/