Gravitule is also known as Patricia, a Torchwood Tweeter based in Paris Tweeting almost exclusively about Torchwood and the fate of the Ianto Jones character. Gravitule joined Twitter on 10th July 2009 which coincides so clearly with the screenings in the UK of Children of Earth that it seems likely that the user is, in fact, a UK based campaigning account using a pseudonym rather than an existing Twitter account.
Patricia/Gravitule has posted around 650 Tweets, follows 85 people and is followed by 51 people on Twitter. Most of Patricia's Tweets concern Ianto Jones and the enthusiasm for this campaign means there are a high number of replies and ReTweets taking place in her Tweets - often passionate conversations about interviews with the creators of the show and their reasons for the decision to kill off the Ianto character.
Gravitule connects bi-directionally (follows/is followed by) to Denise's campaign-heavy @cinderblock42 account. Gravitule also follows fellow campaigner @neurwen and @torchwoodforum.
Gravitule Twitter Stream: http://twitter.com/gravitule
Patricia's Twitter account points to, and I assume she runs/co-runs, the Just Giving site for the Ianto Wants a Pony campaign: http://www.justgiving.com/ianto-jones-wants-a-pony/