There is no copyright in the EU. We have the" Urheberrecht", which functions a little different than the US copyright. In the EU (at least in Germany), copyright cannot be transferred from one person to another. The right holder can only grant rights of use to others.
Be that as it may: At least in Germany it is currently general jurisdiction that contributions in forums (unlike photos, works of art, etc.) do not have the necessary "level of creation" to fall under Urheberrecht (~ copyright).
Together with the terms that should grant the provider of a forum an "irrevocable right of use" (not copyright) for contributions from users, my answer is also "no".