Forgive me another probably dumb question, but I don't mean to be obtuse or sarcastic at all, this is straight up: Even working on projects where we wanted to

Forgive me another probably dumb question, but I don't mean to be obtuse or sarcastic at all, this is straight up: Even working on projects where we wanted to see online adverts, all ad networks were null routed at our border. We saw too much variety of risks in letting adverts traverse the lan. I'm (very) out of touch, but is it expected to view pages complete with advertising - unadulterated - in modern corporate setting? If so, is there good reason for this? Or am I missing relevant firewall tech?