Our world is awash in mis- and disinformation. Conspiratorial thinking and misguided beliefs and attitudes towards science are widespread. But combatting this deluge of problematic information must be done with care. Too often, argues Whitney Phillips, we dismiss the people who consume or propagate such information as irrational. In fact, given the experiences they may have been having on the internet for many years — or what they may have been encountering via traditional media for decades — their views, troubling as they may be, may in many cases be perfectly rational.