At my previous role at Twitch, attackers were spamming our service with ToS-violating content (mostly porn but also grotesque, violent stuff) to an insane degre

At my previous role at Twitch, attackers were spamming our service with ToS-violating content (mostly porn but also grotesque, violent stuff) to an insane degree. The decision was made to temporarily require a phone number on all accounts in order to stream. I argued that phone numbers were easy to get, making this measure unhelpful, but we did it anyway. To my complete surprise, the attackers didn't bother the obviously surmountable hurdle of getting burner numbers. Yes, phone numbers won't stop determined people, but in practice they're surprisingly effective. After my experiences, I believe that's because there's a difference between determined attackers trying to penetrate your system and people "just out for the lulz"