Not quite sure why this is being downvoted but let me put my more "politically correct" hat on.
I don't feel strongly with the presence of the word hack in the same line with engineering. They just don't gel.
I rarely and hardly seen any engineers pulling one-nighter writing code with lack of automation tests. I see a lot of young hackers do that.
I would strongly suggest the downvoters go to InfoQ.com and search for Aditya's presentation regarding Facebook engineering to understand the issues arise for having a "hacker" culture.
And I'm telling you the fact that Facebook albums have had UI bugs; they frequently re-appear after what I felt is a re-deploy of their updates/newer versions of the website
Back button doesn't necessarily work sometime
One can see other people pictures but can't see their album (can't click the "photo" link but can click the photo in their profile page)
On iPhone, often one can't see "more..." pictures.
When I say those bugs in Facebook albums are exceptions, I truly mean it. Facebook can have buggy code yet they probably won't get penalized by their user. None of their user fled for other social networking sites.