https://www.reddit.com/r/Bitcoin/comments/6q319b/shapeshifts_cio_is_an_advisor_for_law_enforcement/
For this reason, SamouraiWallet is looking to integrate an auto-exchanger that is not shapeshift.io.
They also publish all transactions (amounts, times, currencies) on a public API, e.g. https://shapeshift.io/recenttx/100
Check this enlightening topic: /r/Bitcoin/comments/59c1kg/expect_no_privacy_from_shapeshift/
so shapeshift can see whats coming in, and the amounts, but if you convert to monero.. that invalidates being traced if the coins going in are not linked to your real identity.