I have read many sentences on Facebook written by Germans and still can't figure out why they are using das instead of dass in such sentences. For example, a joke I just read:
Jedesmal wenn ein Mädchen sagt, das sie durch einen Unfall schwanger wurde, stelle ich mir immer sowas vor.
Is this a colloquial usage, or what? What does das refer to in this sentence? Do people sometimes use das instead of dass in the non-standard written language?