I've speculated before that it's algorithmically updated in most cases. If 5 people submit a link to the same url and 3 of them use the title "ABC" but the fir

I've speculated before that it's algorithmically updated in most cases. If 5 people submit a link to the same url and 3 of them use the title "ABC" but the first submitted used "XYZ" then at some point the algo changes it from "XYZ" to "ABC". Other than that, active moderation because of excessive editorializing by submitter.