Pros
The team is very passionate and filled with intelligent people striving to make a difference. Lots of after-work (or during-work) events, rallies, and activities to participate in. The team feels much smaller than expected for such a well-known organization (which can be a positive or negative, I suppose).
Cons
A lot is expected of interns, but this is does not necessarily mean interns are assigned the most riveting or substantive of tasks. Often, it felt like a very large pile of busy-work or things that someone has to do so why not give it to the intern? That said, each department/team offers very different internships so I think people were mostly happy with theirs. Mine was a great boost to my resume but I didn't feel like I got much out of the experience.