With regards to the lawsuit – that's already in process, however we need all withdrawals to be blocked for now in order to not lose the money. But the support is inappropriately slow in that case.
For anyone concerned, I've also found a link that may help you in the future to escalate the ticket and probably get a reply:
www.kraken.com/escalate-your-ticket
Since Kraken is a U.S. based exchange, I think you can compel them to halt all transactions on that account pending court decision. I hope their support may be able to help you especially if you could provide convincing proofs to support your claim even there are issues involved but if this is not yet resolved within a reasonable time frame, you can pursue your case to the one who stole your account where you could present your evidences to prove the veracity of your claims.
Thank you for escalating your support request. We'll make certain one of our Account Access Specialists will be with you as soon as possible.
Glad for your response to attend to your customer's issues. I hope the resolution of his case will be attained very soon.