Digg's v4 release on August 25, 2010, was marred by site-wide bugs and glitches. Digg users reacted with hostile verbal opposition. Beyond the release, Digg faced problems due to so-called "power users" who would manipulate the article recommendation features to only support one another's postings, flooding the site with articles only from these users and making it impossible to have genuine content from non-power users appear on the front page . Frustrations with the system led to dwindling web traffic, exacerbated by heavy competition from Facebook, whose like buttons started to appear on websites next to Digg's. High staff turnover included the departure of head of business development Matt Van Horn, shortly after v4's release.