Text messaging: does it harm student writing?

Some teachers say text-messaging could be taking a toll on students' academic writing. Teachers have noticed -- and students admit -- that common text-message abbreviations and lingo are being included in student writing. Teachers also say students often do not know the difference between social and academic writing. Common mistakes include using the letter "u" instead of "you," and using "r" instead of "are." Details in this story from Minnesota.