I do it quite a bit, and I can't be the only one. Can you imagine the shit that has been said, but has not been said? What a read some of it would have been, good or bad. These days, the most common reason (there are others) that I decide not to submit a reply that I've typed out is because upon reflection, I suddenly realize that I just can't be fucked getting into it all after all. Nevertheless, the exercise is almost always still useful in a 'dear diary' sort of way, and any research I might have done often comes in handy at some other time anyway. Some of the contributions I've withheld might have stirred up a hilarious amount of shit, actually, and others probably bordered on infraction-worthy. But that's the great thing about forums isn't it? You always have a chance to think long and hard before you open your mouth, because it's a forced multistage process.