Legit Bitcoin mixers always delete logs and whatever other information that is connected to your mixed/clean coins. That's the main benefit of Bitcoin mixers. It saves you some extra headache.
That’s it, but there are some problems. Simply put,
NEVER EVER use this pseudo-legit services :
Bitmixer.io (cloudflare)
Coinmixer.se (cloudflare)
Darkbit.io (cloudflare)
[banned mixer] (was cloudflare or incapsula as i remember. now vps. that's much better then those that use cloudflare coz server located outside usa but using VIRTUAL server is sucks)
First of all,
the log of your actions will 100%! be recorded and investigated by US law enforcement agencies. I think European law enforcement agencies will also gain access to them.
Secondly, the log will be made available to any lawyer, attorney, court, etc under any reasonable and legitimate request.
Even if you don’t violate any law, using these services is like walking down the street with a dummy grenade. You may at times be dealt with by the cops without any reason whatsoever and enter into their black book.
I'm not even talking about those who use these mixers in some illegal activities. In this case, instead of unknowingly surrendering themselves through such service, it’s easier and cheaper to go to the nearest police station with their own money and surrender without intermediaries.
You may ask why this is so? There are no secrets here for many people. So much has been written on this forum about these wonder services. The problem is that these services use VPS (not dedicated server) or Cloudflare,Incapsula anti-DDos. How does such anti-DDos work? Cloudflare fully decode all traffic (https) on its resources, analyzes it, filters and then passes it on to the wonder mixer. There is no anonymity whatsoever. Major legal companies undoubtedly analyze the traffic of such "sweet" clients as Bitmixer with utmost care. And if any law enforcement agency will need some log, they won’t need to search for the owners of Bitmixer – logs can always be obtained from NSA, where they get to from Cloudflare by default.
To achieve the best mixing effect, the wonder services recommend using web wallet from blockchain.info and buy Bitcoins from Localbitcoins.com. It’s hard to think out a more idiotic act given the fact that both blockchain and localbitcoins also use Cloudflare. In this case, bitcoin purchase log will also be attached to the log of your actions on the mixer with your name, bank account, credit/debit card number and so on.
Yeah, that's a royal clusterfuck. But you would say that these sites have tor mirror.
Yes they have. However, the way these people organize their services in a clear Internet is the same when doing so via tor.
Of course, when using tor, it’s more difficult to set up clients, but I think these services are coping. 
