Up to 14 cans of diet drink a day considered safe for 70kg person, as WHO says sweetener is ‘possibly’ carcinogenic in larger amounts
So maybe the huge worry people had after the news that WHO would classify it as cancerous was a little too much. I think the media could have reported on it in a bit more responsible way.
From what I read, in the 60s there was this idea that intestinal flaura would break it down into sulpher compounds that could cause cancer. A bunch of countries banned it, but later research suggested that it's not that big a deal, so a lot of countries unbanned it.