When Lars Bjørnshauge founded a website to index open-access journals in 2003, just 300 titles made the list. But over the next decade, the open-access publishing market exploded, and Bjørnshauge’s Directory of Open Access Journals (DOAJ) along with it. Today the DOAJ comprises almost 10,000 journals — and its main problem is not finding new publications to include, but keeping the dodgy operators out.