You have nothing to lose but your . . . er . . . something-or-other.
A conlanger is a creator and/or student of conlangs, i.e. "constructed languages." These are primarily "art for art's sake," distinct from auxlangs ("auxiliary languages") intended to facilitate international communication. So, no, this group hasn't anything to do with Esperanto, or Ido, or Interlingua, or [insert IAL here]. Instead, think Quenya, Klingon, Brithenig, Breathanach, and all that other fun stuff.