Yes, Black people should put white people's fears at ease. Instead of letting the poor white man suffer through an entire train ride, watching you and clutching his bag, just rob him blind as soon as you get on the train so you both can relax. Etc.
None of us are easily separated from our misconceptions and stereotypes. If I spot a white man wearing dark clothing and a shaved head with tattoos on his body... he's a skinhead. If he doesn't attack me, he is a skinhead in a particularly generous mood. He is not going to do or say anything to put me at complete ease. I presume the opposite is also true.