I stumble over it more and more often, using tumblr. As a non-native speaker it's really annoying. Because we wade into the deep waters of english internet communications to strengthen our language skills. But while I understand that nobody outside of English class speaks Oxford English, I noticed that nowadays it is pretty unlikely to keep your English on an acceptable level for job applications using the internet. Most English and American tumblr bloggers, Goodreads reviewers and Facebook users seem to be worse in writing English than I am. And even though my college ranked me as 'native speaker level' I simply do not understand what they are trying to tell me. While I can communicate with French, Russian and Indian citizens (and mostly Brits as well) in English, especially writing with Americans becomes more and more difficult. Even though I read novels in English and watch most TV shows in original version as well.
So while all those little quirks might seem like natural language evolution to those who use them, they are making it harder to communicate. In a time when English is spoken (or at least written) by almost everyone on the planet and the internet brings us all together, those people segregate themselves again.