@Advocate,
Yes there is racism within the black community. I also think selective outrage in the black community exists and while some African-Americans target unjust racist actions made by others, they remain silent to the current issues that remain internally. As far as this so-called "knockout game" is concerned, let me say that this stupid game has been going on since the late 90's in which immature adolescents have been doing, targeting unsuspecting victims across ethnic cultures.
The same can be said about kids who drink "lean" (cough syrup with sprite/or flavored soda) or the concept of "thug culture" post Trayvon Martin, whenever biased political media obtains information of this kind, they make it seem apart of an ethnic culture as opposed to a culture of a generation--which is what you did mentioning the knockout game.
Speaking of selective outrage and racism, what I always found fascinating that terms like "race huslting" "thugs" "saggy pants" " people with guns" were always issues but with little concern especially in black neighborhoods, but when white kids are being shot in schools or bringing guns to school, now we are ready to discuss gun control. Or when the likes of Justin Bieber drink cough syrup and soda, now we're ready to I.D people who purchase cough syrup with codine, or when Trayvon Martin was shot now we educate people on what "lean." Or when Tupac and groups like Bone Thugs N' Harmony advocated "Thug culture" in the 90's being a thug was never a problem.
I say all that to say the current issues we face today has always existed in the black community, and because they have always existed subsequent to perpetual systemic racism promoted by some whites, some blacks therefore became the very evil they complain about. So-called black racism, is reactionary to historical white racism so before we get into discussing this we need to understand the sociological foundation of such phenomena.