Thanks a lot for your replies.

I was asking because I noticed the mixing transactions following the 4200 BTC inputs.io theft - https://blockchain.info/en/tree/96033579 - had "Relayed by IP : Blockchain.info". It got my hopes up that those transactions were performed using Blockchain.info, which would leave an auditable trail behind (eg IP access logs, maybe a wallet id ?)

I understand it's a blatant violation of Blockchain.info's privacy policy for them to disclose that information, but should the law get involved, it would be useful in tracking what happened.