Motes ...
Aha! I knew I'd read of this somewhere before...
One of Niven's ships used such a laser to maintain contact with earth. The crew didn't think of it as a weapon therefore the craft was determined to unarmed by a Kzinti telepath. However a few crew members knew better and used said laser to obliterate the Kzinti when they attacked.
Q of the day: Why is 'Kzinti' already in my phone's dictionary?