All the time. When you have a keyboard in front of you, not using decent punctuation, capitalisation and so on is just lazy. Either that or you're just a moron. Or both.
Like Frequen-Z (above), I also do the same when sending a text. On older phones it's was quicker and easier to use "txt spk" but now it's so much easier, especially now predictive texting has gotten better. I can only speak for my phone on that matter so hold the flames!
YouTube comments are a classic example of the sheer dimwittedness of the majority of internet users but they do get everywhere. Everywhere I go I see retarded comments with not even a full-stop at the end. That and the hideously irritating paragraphs with no punctuation at all.
There is only one place for no punctuation and Yahtzee has bagged it!
Wardy