One tweet, in which it was claimed that its pub staff would not be wearing poppies for Remembrance Day, resulted in hundreds of outraged calls and emails to its head office.
One shareholder attended the firm’s annual general meeting to express his concern about the news and pose questions to the chief executive.
Other practical jokes included false invitations to job interviews and fake voucher codes, all of which “took up valuable staff time and bewildered members of the public”, said Mr Fox.
Partner with law firm BLM, Steve Kuncewicz, said the case was “significant”.
“Wetherspoons had clearly exhausted all their options as this has been going on for years. It shows that brands are not entirely powerless, but they also have to consider whether they are going to war with their own fan base.
“I doubt this will be the last case like this we will see.”
Twitter does allow parody accounts, but only if they are clearly not attempting to impersonate official pages.
JD Wetherspoon runs 900 pubs around the UK and Ireland.