What are your pet punctuation, spelling, and English usage peeves?

There is no better research tool than the Internet. It enables you to find information on just about anything within seconds. It also gives bloggers and people posting on popular online forums like this the chance to present their views to a worldwide readership of thousands, millions even. This can be a good thing, but it can also be a bad thing. Prior to the advent of the World Wide Web, when everything we read was in hard copy form, most of what we read had to be checked by editors and sub-editors before it was allowed to go to print. The Internet, however, has all but eliminated this level of scrutiny. Anyone can post anything online regardless of how poorly written it is. What this has done has spawned a plague of misspellings and bad grammar, owing to people who don't know their way around the written language as well as they ought to copying the literary blunders of others. A classic example is disappoint. How many times have you seen it spelled dissappoint or dissapoint online? Then there is the incorrect use of loose, as in "I'm afraid you're going to loose all your money." But my biggest pet peeve is the redundant expression "the reason why." Why is the reason, and the reason is why, so only one of these words is necessary, yet even seasoned journalists often use this expression, which admittedly has been around a lot longer than the Internet.