Someone who posts to the Usenet newsgroup alt.alien.vampire.flonk.flonk.flonk, which has nothing to do with aliens or vampires.

a geek affliction whereby a poster on a forum disregards the last post and continues with his or her own; this is also called crossposting, and is a horrible disease.

People exhibiting this type of behavior show no regard for the edit button, and usually have no idea the cure is quite simple: refresh, edit, and re-submit. While in the throws of a Linkitis-fit, afflicted posters will generally never delete their infected post, forcing other posters to take up the slack, delete THEIR own post, and make some sort of a cheeky reference.

This affliction occurs quite often on the Lostpedia forums, and was first discovered in late August of 2007. Named after Link McCloud, Linkitis is only getting worse lately; scientists are currently unable to figure out why this continues. Remember: refresh, edit, resubmit.