A number of posts naming Devil's Dyke were removed and some of the group's members were removed by Facebook, it has been reported.
Facebook has acknowledged the error and a spokesman offered their apologies.
Retiree Glenys Horton is one of the moderators on the 'Brighton Life' Facebook page, which boasts some 58,000 members.
Glenys said she enjoys using the social media platform for genealogy, chatting with friends and sharing pictures
She said: "I don't know when it all kicked off to be honest but I have become aware of it after seeing messages from people on the group saying they have been banned by Facebook. It's just ridiculous but I understand because it is not a person sitting there moderating something.
"It must be a computer algorithm which is picking up words like these and may not know what a dyke is."
Dyke is used in places names all over the country and as a surname.
Glenys added: "The word has been around since the 1300s. There's dykes everywhere. It think it has been lost in translation."
She also compared the mass-banning to George Orwell's 1984.
"What else are they going to ban? One of my friends said 'hey-ho' and was given a short ban."