Can the MercuryWallet.com seize my coins?

In the Mercury protocol, the Mercury server securely deletes expired private key shares (via Intel SGX based HSM) while it never has custody or control over deposits and cannot be compelled to confiscate or freeze funds. If the Mercury server disappears or is uncontactable then the owner will have to wait until the lock-time of their backup transaction to regain full control of the coin.