Yes, alas, the online world does seem to decrease people's skills in word usage, spelling, punctuation, grammar. There are seldom proofreaders for all those blogs, or even for the articles in online newspapers and such.
8 Words the Internet Loves to Confuse With Other Words
by Christina H, Aug. 30, 2011
As the author of this article says, "there are still a lot of other rogue (not rouge) words out there mixing with their homophonic or lookalike cousins and wreaking (not reeking) havoc on news articles, blogs, and forums everywhere." She illustrates word misuse with hysterical headlines and quotes from online sources, and with wildly amusing pictures. Do go read the full article. But make a note of these words in your personal proofing list.
1. Bear/Bare - A large, furry carnivore - naked. As the article author says, "I would never dream of insulting you by explaining the difference between bare and bear. Third graders know this. Nevertheless, people mix them up all the damn time."
2. Tack/Tact - Tack has several unrelated meanings: a change of direction, a pin, or the saddle and all that stuff you put on a horse. Tact is a kind or socially acceptable way of talking or acting so as to avoid offending others.
3. Hanger/Hangar - A hanger is something you hang things on. A hangar is where you keep aircraft.
4. Principal/Principle - Oh year, I see this error all the time in lots of places. The principal is the head of your school or the main person in some group. A principle is a basic belief about what's right and good. We would like every principal to have principles.
5. Per Se/Per Say - I've never actually seen this error, but according to the author of the blog article, it is rampant online. There isn't such a word or phrase as "per say", it's just a mispelling of per se.
6. Epitaph/Epithet - I see this misused/misspelled all the time, and it cracks me up. An epitaph is what they carve on your gravestone; an epithet is a term used to characterize something, often meant in an insulting or offensive way. Let's hope your epitaph is not an epithet.
7. Wary/Weary - When you are weary, you're tired; when you are wary, you are cautious and concerned ('ware' like in 'beware').
8. Regimen/Regiment - A regiment is a military unit; a regimen is a routine or a planned health schedule. So you don't have an exercise or diet regiment (although the soldiers would certainly be in good shape, if so), it's a regimen.