Beginning in 2013, the three major internet search engines Google, Bing and Yahoo introduced a warning “pop up” which appears on the screen if a user searches for common search terms associated with child pornography (i.e., Lolita, pre-teen girls, young boys etc.).
These warnings are not also automatically sent to the FBI as is sometimes thought. There are several well-known scams which can trap people receiving such warnings into sending personal information. Never do so!