In the strictest sense of the words, most atheists are agnostics. It seems redundant to use both, to me. In a more popular sense, people I know use agnosticism to describe their belief that something could be out there, some force or cosmic spirit, they just don't know for sure what it is. I know that it is a perversion of the true meaning, but to avoid long explanations and confusion over connotational shortcomings, I prefer to simply use atheism as the correct term for my position. I think this is where A7 is coming from, as well.
I suppose my real problem with it is that the repurposing of agnostic doesn't provide anything useful. There are numerous other words that could be used in place without confusion. If one wants the meaning of 'undecided', isn't it more clear just to say 'undecided' in place of 'agnostic'?
I completely agree with you, but most people seem to think that "agnostic" makes them sound cooler than "undecided." Or perhaps these people are frightened by the misconception of "atheism" as a staunch declaration that there is definitively no god. It all stems from a fundamental misunderstanding of the difference between knowledge and belief.
How is it redundant? How many people are truly gnostic atheists or gnostic theists? Even allowing that belief in knowing qualifies as gnostic, that still leaves a small amount of people in the atheist camp. And I'd argue that the doubt that many theists constantly battle, their crises of faith, constitutes a level of agnosticism.
I'm agnostic about almost everything, if not everything. I see it as a given that doesn't need to be paraded about simply because we are now speaking of religion. And, no, I don't believe that "agnostic" need be repurposed either (even if many have done just that), but I think it is rather useless except when talking with certain theists or pedants.
As I have said before about the couch in my living room that I cannot see from where I type, I really don't know that it's there when my gaze is averted, but that doesn't mean I need to live in a world of false equivalence and glumly admit that my couch might not exist at moments when I am speaking about it and do not have it in sight. The probability of a God or gods is so low, that being "agnostic" about it seems a trivial distinction that atheists can typically do without.
But if people like to call themselves agnostic, it's not the end off the world. I still see it as redundant because it should be a given among most, if not all, people.
I can safely assume that no one alive today knows if a god exists or not. I can't know that to be absolutely true, but I am certain enough that for all intensive purposes, I'll just say that I do know.
Now if a belief of knowledge is what you mean, then I'd allow that some people really do believe that they know. I'd still argue, in good nature, that they are the stark minority, regardless of theistic titles.