Insecure high-school kids latching onto whatever cultural or subcultural stereotype they can in order to 'fit in.' This is a manifestation on an undifferentiated ego-mass striving for conformity and order in a complex and difficult social environment, such as high-school. Most of these kids will outgrow it by their mid 20s. And, will discover that 'being themselves' is the best option of all.
Middle and upper class Black kids trying to be 'gangsta.'
Middle and upper class White kids trying to be 'punk.'
'Derek is such a poser. He talks all 'street' and listens to all the latest gangsta-rap from LA. When in fact, he grew up in Georgetown and his dad is an executive at IBM.'