21% of Atheists believe in god. What this means is that Atheism has become a cultural designation, rather than a theological statement. Some are likely declaring themselves atheists as a statement of hostility to organized religion, rather than to God. ~Steven Waldman, on new Pew survey numbers

What it means is that one out of every five “atheists” doesn’t know what the word atheist means.  It is certainly some kind of statement–an ignorant one.