I am trying to install a driver for my Brother printer/scanner (DCP-9020CDW). Brother provides Linux drivers (printer drivers are libre; scanner drivers are not). One of the requirements before installing is to run
$sudo aa-complain cupsd
which, according to the manual, means that "security policy is not enforced but rather access violations are logged to the system log".
Asking to disable security policies before installing new packages/drivers from outside the official repositories sounds suspicious to me. Am I being too paranoid, and is there anything sensible I can do apart from just not using my scanner*?
*There's an open-source PPD file for the printer, though I haven't tried installing it yet.