submit their brochures
with huge penalty to vendor if later found to have submitted fake brochures. To verify, enforcement agency could create sting organizations, pretending to be customer.

'mandated backdoors in the telco equipment we produce, using the term 'lawful intercept'. And now you're surprised and upset when bad people use these same backdoors?'
How many of the same vendor companies lobbied against export controls? The bad guys are willing to spend money. Their suppliers (the vendors) will then spend (invest) some of the received money to lobby their home government.