A fangirl is the worst kind of female fan. She will wallpaper her room with posters of her lust object but will fail to capture his character in any way in her fanfiction. She will pepper chatrooms and author's notes with praise for a canon character's "hottness" (two "t"s included) and will generally demonstrate zero maturity and emotional restraint. She hates her lust object's significant other, couldn't care less about canon, and populates the biggest fandoms to a terrifying degree. Harry Potter, Lord of the Rings, and Pirates of the Caribbean are all infested with fangirls, who are consistent perpetrators of Mary Sues and canon rape. The overwhelming majority of writers in these fandoms is female, so the fangirl's counterpart, the fanboy, is rarely encountered. When he is, the Canon Protection Initiative treats his work with the same contempt as that of the fangirl. PPCers are very insistent on this one point: a fangirl is not defined as a female fan. To call a PPC member a fangirl is an insult, whether or not the PPCer is female. We are fans, period.
There is a cure for the common fangirl. It is known as the OFU. The Official Fanfiction Universities advocate forcing fictional fangirls to learn, through pain, to be better writers. The OFU fangirls will attempt to glomp or stampede on occasion but are always held back by their wardens, the university minis. Fictional fangirls are also the chosen cuisine of mini-Balrogs.
Several PPC agents are OFU graduates and thus ex-fangirls. Such agents are encouraged to attend Lusters Anonymous.