Markle gained plaudits across the globe when video footage surfaced at the London's Royal Academy of Arts last September of the Duchess stepping out of the vehicle and having the temerity to shut the door behind her.
They have even enlisted Instagram to help. It's not acceptable to post abusive, sexist, racist or threatening comments on our platforms or anyone else's.
Speaking to Hello!, who launched the #HelloToKindness campaign in a bid to encourage positivity online, the source said: 'The Palace has always monitored comments but it's a hugely time consuming thing. Over the course of previous year, with hundreds of thousands of comments, there were two or three that were violent threats.
While royal aides have stressed that the majority of comments being left on the official Kensington Palace social media accounts are positive, a Palace source told Hello that they have also highlighted that teams are spending hours reviewing old material and moderating comments under posts.
They created the #HelloToKindness campaign in an attempt to change the direction online discourse is taking at the moment.
'They can block certain words, but some of it is quite serious.
'Arguments about who looks more appropriate, for example, that turn into personal attacks on other users.
Royal watchers praised the "down-to-earth" gesture when the Duchess closed her own door at her visit to London's Royal Academy of Arts in September.
"And you will love some of the pictures in my book also to refute any of your nasty troll gossip that we did not have a life together", she adds as a response to her naysayers.
Markle's mega-fans took to the internet in droves to comment on her "humble" and "down to earth" attitude.