Do de-facto atheists make claims that God doesn't exist?

Answer 1

De-facto atheists do not believe in God, but whether or not they seek to try and claim this outspokenly or to just keep their non-belief to themselves depends upon the individual. The majority of atheists do not go around trying to disprove the existence of God and attempting to convert others to a state of non-belief, partly because it simply isn't POSSIBLE to prove that there is no God but also because they respect other people's right to hold spiritual beliefs, and regard it as inhumane and cruel to try to deprive believers of their faith. A minority of outspoken and fanatical atheists DO preach that there is no God and make a big thing of it, i.e. Richard Dawkins, Steve Jones, Stephen Hawking etc., but however eminent and clever such people may be they are not typical of atheists as a whole, and are actually extremist about their feelings because deep down they suspect that God DOES exist and, for some reason, are frightened by the idea, so feel the need to go into denial and to rally support from others to prop them up.

Answer 2

According to a definition by Richard Dawkins,

1. De facto atheist. Very low probability [that God exists], but short of zero. "I don't know for certain but I think God is very improbable, and I live my life on the assumption that he is not there."

Answer 3

Try not to confuse yourself with adjectives regarding atheists. An atheist is simply a person who lacks a belief in gods. Therefore, an atheist does not make claims that gods exist.