Beeing one of the non-native english speakers on this BBS, I feel the need to state that I would not mind at all if I were corrected and gently (or even not so gently, I can take quite a bit ) pushed in the right direction. In fact it's a couple of years ago that I was taught the rules of english grammar. The use of the language has become somewhat automatic, just like Reverend Michael West describes.
However, as soon as one starts to use a language naturally(with which I mean thinking in the other language rather than modelling a sentence in your native language and then translating it), one starts to develop bad habits, that are hard to get rid of... even harder if you don't know about them. I havn't used a spell checker until now(which will change in the near future), but I did proof-read my posts. I do realize that correcting every one of my mistakes would be a full time job and I agree with _ynot's point that it would seriously contribute to the noise level.
But beeing told about unbearable faux pas, would surely have positive impact on my future posts.

Oh, and as a side note ... I found French grammar to be much more complex than the english equivalent.

EDIT: Typo