On: A Startup With a Way to Filter Botnet Traffic Gets Funding

My personal experience with comment/forum spam bot networks is that at least 90% do not understand javascript. The ones that do tend to have extremely realistic traffic patterns and the ability to solve captchas. I suspect those are actually real people with incredibly crappy jobs, not super-intelligent Selenium-powered bots.

Comment/forum spam is different game than botnet ad fraud. The latter executes JavaScript by design since it's often necessary to load the ads.

see the charts from Incapsula in this article which show a third of the bots are not executing javascript https://www.linkedin.com/today/post/article/20140623200557-8...