Sometimes it takes but a single pebble to start an avalanche. On January 21st Timothy Gowers, a mathematician at Cambridge University, wrote a blog post outlining the reasons for his longstanding boycott of research journals published by Elsevier. This firm, which is based in the Netherlands, owns more than 2,000 journals, including such top-ranking titles as Cell and the Lancet. However Dr Gowers, who won the Fields medal, mathematics’s equivalent of a Nobel prize, in 1998, is not happy with it, and he hoped his post might embolden others to do something similar. It did. More than 2,700 researchers from around the world have so far signed an online pledge set up by Tyler Neylon, a fellow-mathematician who was inspired by Dr Gowers’s post, promising not to submit their work to Elsevier’s journals, or to referee or edit papers appearing in them. That number seems, to borrow a mathematical term, to be growing exponentially. If it really takes off, established academic publishers might find they have a revolution on their hands.