Everything has it's limits. I can tolerate some things, like run-on sentences (to a point, if it's like five lines with tons of commas then that bothers me), but I hate it when people use tons of unnecessary punctuation (lol!!!!!!!!!!!!!!!! as an example, I think by the second exclamation point we get you're yelling), and write "sentences" like "met u @ the mall 2nite." Seriously, it isn't that hard to write "Meet me at the mall tonight."
D: