As reading recedes into being a specialized skill many people are on their own when trying to spell what they hear. "You're" sounds the same as "your", "they're" sounds the same as "their". The logical difference is moot. On teh interwebz a select picture is accepted as a valid response (we see this on TB too). No further argumentation need be attached, and the skill of decoding the intended message in a particular image constitutes a metalanguage that brings us around to pictograms - the beginnings of writing. Strange.