[skeaker]

The word "just" is doing some heavy lifting here... To "just" do this, the agent would need to more or less completely take over the building infrastructure before Mullvad could react which is a lot easier said than done. Even if it were trivial it's still quite a few cuts above any competing VPN service.

[Cyphase]

IANAL, but I think "reacting" to a warrant in the way you're implying might be illegal in some places.