server/public/javascripts/activity.js
function filterVerbs(activities) {
    return activities.filter(function(activity) {
      var showing = verbsShowing[activity.verb];
      if (showing == undefined)
        showing = verbsShowing["other"];
      return showing;
    })
  }
function filterVerbs(activities) {
    return activities.filter(function(activity) {
      var showing = verbsShowing[activity.verb];
      if (showing == undefined)
        showing = verbsShowing["other"];
      return showing;
    })
  }
Filters and returns only activities that should show based on selected filter.