His campaign eventually started using Nazi imagery suggesting various opposition groups and protestors should be sent to concentration camps.
Facebook pulled the ad. Around the same time, he used Twitter to (successfully, apparently) incite lynchings.
Pulling a few Trump campaign ads was too little too late, and now people are boycotting Facebook.
Here is a link to a story about the ad. Don’t take my word for it: https://boingboing.net/2020/06/18/trump-ad-uses-nazi-symbol-...