This is false. Sufficient evidence was found in the 40s, but tobacco was seen as a threat by some scientists/doctors way before. And today we have a much better understanding of epidemiology, so any cancer glyphosate enhance would have been discovered already. And we did: NHL.
We knew earlier, but I'm sorry; I thought we were talking about actual proof, not lack of knowledge and/or marketing. If nothing could be used by the general public until 'proven safe' you would be living in a cave and discussing this via carrier pigeon.
My router has a whitelist, not a blacklist. Which is safer?