Discernment, a gift from God that should be used.
Yes, Blacks are dangerous in the great scheme of things. Given time with individuals one can discern that certain blacks are not likely to be dangerous, but strangers and groups of blacks should be avoided. Most of the time you will be ok, but after XX encounters odds are you will meet a bad apple(s). One could argue the same with all groups, but just playing the odds, blacks are far more dangerous.
Sorry (not sorry) if that offends anyone.