Someone who has completely misunderstood the point of hash tags and so uses them in an ridiculously excessive way to try and make themselves look cool/a social networking enthusiast/look like they have loads of twitter followers, friends etc.
However they just end up look stupid and embarrassing.
"oh crap I just got a parking ticket #GODIMANIDIOT Oh well, im getting drunk tonight #ITSGOINGTOBEABIGONE #WASTED #IMSOFUCKINGCOOLITSAJOKE"
John "Oh help, did you see Mikes twitter today"
Celine: "ew yes, he's a total hashtwat #twat"