Ebonics is (for some reason) considered a separate language altogether. However it (sort of) uses common english 'grammar' (I am hesitant to make this a claim; let's just say 'I tend to see it as using english grammar sometimes ). Anywho:

What is your opinion of ebonics?
What do you have to say about people who mix languages in their sentences? Does it bother you to schalten Sie plötzlich Sprachen tout en lisant une phrase ?

Ebonics implies an African origin. I prefer 'black english' which embraces other 'black' cultures, including haitian, jamaican, and other cultures. Some university courses actually teach black english (not to be confused with ebonics).

As for randomly switching languages, as long as I understand what it means, I have no problem with it. I try not to, but when I speak Chinese, I sometimes pause, think, and decide to finish the sentence in english. *sigh*

Also, since it's not technically a fallacy to speak random languages within a sentence/paragraph/etc, my only argument against switching languages for whatever reason is that it is unclear, or contributes to a sense of unclearfulness in expression.