I would love to have a general conversation around mixers and if they are legal. I've heard both sides. Would be great to have someone involved in the legal side of things like Ciphertrace or a regulator to shed light on this topic
In general, Bitcoin mixers are
not illegal, but agencies in different countries always track Bitcoin transactions and investigate such services to prevent money laundering and other types of criminal business. For example, on May 22, 2019, Dutch police has seized the "BestMixer.io" tumbler which may have provided a high level security for every Bitcoin transaction. As far as I remember, the authorities claimed that Europol has analyzed the databases from 6 confiscated servers and collected information regarding transactions between customers of this service. Therefore, every user who wants to mix bitcoins should choose a
reliable Bitcoin mixer.
I guess that Bitcoin transaction fees increased sharply in May 2019 because "BestMixer.io" has been shut down. Perhaps people
massively sent their BTC coins to another Bitcoin mixers in order to keep their privacy.