You can't remove all the bad videos any more than you can remove all the cholera from the river. Do you know how we protect populations from cholera? * isolate

You can't remove all the bad videos any more than you can remove all the cholera from the river. Do you know how we protect populations from cholera? * isolate the source and provide supportive care (infected people). * make sure the source is downstream of the population (livestock). * On inland waterways where multiple cities depend on the same river, you filter the water until your sampling demonstrates it is below the limit of infectivity. It took a while to figure out the limit of infectivity for cholera. You still do the work. It's going to take a while to figure out the limit of infectivity for videos, github, etc. Also, you really have to let go of this base rate fallacy bit. The methods I describe are entirely general. Also, since you keep talking about the base rate fallacy, please understand I live in the realm of diagnostics. I understand the problem. So, since you brought it up: The difference between the Bering strait and the Mississippi river (not far from where I grew up) is trivial on the scale of cholera. Flow rate of Bering strait: ~ 2.1e4 m3/s. Flow rate of Mississippi: ~ 1.7e4 m3/s. Volume of a V. cholera: 1.17e-19 m3. In either case, the difference is 21 orders of magnitude. If the Bering strait was the lifestream of all 8 billion humans alive today, finding a vibrio in the flow would be equivalent to finding a single person generating half a picosecond of violent video. The point is not finding all of them. The point is sampling well enough that you can calculate the limit of infectivity. Once you can do that, you can start engineering solutions at social scale, e.g. move the village, move the cattle, install filtration. Maybe even fund development of new filtration systems.