If you ever feel the need to lock your interactive session via PowerShell, here’s a function that can do this (and also illustrates how to use low-level API functionality):
function Lock-WorkStation { $signature = @" [DllImport("user32.dll", SetLastError = true)] public static extern bool LockWorkStation(); "@ $LockWorkStation = Add-Type -MemberDefinition $signature -Name Win32LockWorkStation -Namespace Win32Functions -PassThru $LockWorkStation::LockWorkStation() | Out-Null }