Mixing is kinda getting turned upside down, so basically a mixing service is to bring a disconnect between address, but that isn't really that private anymore. Plus they can steal your funds. A new mixing type has been created, which is coinjoin, and it aids more on that you are confusing people, and making it so mixers can't steal your funds. https://bitcointalk.org/index.php?topic=279249.0 <<
Blockchain taint analysis works by doing a search for where two or more addresses are connected meaning they were used in the same transaction.