I've seen this one coming for a long time. And I don't blame it on Instant Messenger type things. All the rave mailing lists I've been on have had people typing in this way for at least 8 years. Bleh.

Nu Shortcuts in School R 2 Much 4 Teachers. As more teenagers socialize online, teachers are finding that Internet English is popping up with increasing frequency in school work. By Jennifer 8. Lee. [New York Times: Technology]