Racism

In real life, now, racism still exist. For example, most adults, or teaching website tells us not to tell others about where you live. And they usually use a foreign black worker as example. They would say you should not give strangers your personal information, like when you go home, what time you are alone at home. And for some reason, the stranger is either black workers or young gangsters. This obviously shows that the blacks has a symbolism of people who commit crimes, or people who do bad things, people without moral value, because they are from a country where families have no decent background. I think this is definitely not true, they like us are humans, jut that they are foreigner workers, what makes us think they are most prone to commit crimes?