This is one of the useful tactics that unions will use when they aren’t legally allowed to strike for one reason or another, they will engage in large scale “work to rule”, which is pretty much what it sounds like, you do your work following the rules to the letter and no further, stubbornly by the book no matter how inconvenient or unproductive or disruptive the rules are when you suddenly start following them exactly.

It’s particularly effective if the rules are a large part of their collective grievances with management, as it highlights to all involved that the current rules need changing, and can sometimes result in fairly quick and positive changes since it demonstrates to management that the current “rules as written” are not the most fiscally effective set of rules for running the business.