DC Street Art

Hi folks, sorry I've been a little MIA lately. The last week has been a busy one with work deadlines, friends in town from Singapore and preparing for my parents' upcoming visit to DC (hooray!). But I thought I would put together a compilation of various types of art I've happened upon in the streets of DC. There are some others here and here.  

 (anyone know where can I get a copy of this sticker?)

(the three previous pictures feature an installation that is no longer in existence. It has since been painted back to the drab rear wall of Whole Foods it once was. However, the artist has since added the art in the following picture to add some more flavor to the building's exterior. I believe this is the work of Shepard Fairey, a guerilla street artist known best for his Obey campaign as well as his iconic Obama poster). 

Have you seen any of these, or other provocative/fun/colorful street art around DC? Do you think it's distasteful or a necessary form of expression?