If you really want to rid society of social injustice, you could take it to the streets, although it's not really clear how a white British rapper's going to be much help. Or try a less conflicted, dope looking approach, in Unscripted Clothing
Recently re-headquartered in SF from SoCal, Unscripted's a full-fledged line of socially conscious streetwear made by dudes who hope their threads -- some graphic'd up with tastefully overt messaging, some not so much -- will spark debate and raise awareness around big picture issues, a la the Great More Cowbell Debates of '06. The tees that're most explicit are exemplified by "Justice for All", a woman crying out before twisted masses of black and white, her head wrapped in a scarf of Iranian green; "Back Fire", a gun barrel twisted back toward its brandisher (a statement on gang violence); and the silhouette of an African boy crouched and clutching an AK-47 in "Child Soldiers", which, unlike Toy Soldiers, doesn't star Rudy. Cut and sew pieces don't feature graphics but're juxtaposed with statements on the shortcomings of the public school system on UC's site; looks range from the "UN Cardigan" (a drapey number in sheer white or black cotton with six buttons and silver/teal logo embroidery), to the dark blue, poly/rayon blend "Graduate" button-down shirt/jacket that yearns to be unbuttoned by the cold, dead hands of Anne Bancroft
Rounding out Unscripted's current line's a bevy of headwear: a fitted black cap with "UNSC" in big varsity lettering, logo beanies in black, brown, and green, and the long ear flap-having Eskimo cap, so you can stay warm on the streets, especially if you're a pasty Brit with a crew cut.