You obviously have no grasp of the english language (or Internet Pet Peeves)

When the person demonstrates that they are perfectly capable of forming coherent and understandable sentences, but decide to use bad grammar or misspellings intentionally, then I dislike it in particular. Every once in a while for emphasis or attempt at humour, I don't mind (eg. "teh"). If it happens frequently, I dislike it and agree with the people who point it out.

My pet peeve relates to my posts as well as some others. I always have 2/3 spelling mistakes, and sometimes I don't bother to read over the post again to check for spelling mistakes. 80% of the time it's due to my laptop keyboard, and the other 20% is due to my shoddy typing. If I see repeated bad grammar or spelling mistakes, I'll flinch, but not think too much of it.

Jam it back in, in the dark.