If you go to the London hipster map. I live square dead in the middle of it (the Shoreditch triangle). Granted I've only lived here for 4 months but the only 2 bad things that I've seen were:

1) Someone puked in the alleyway that leads to my door. I walked around it. 2) One day when coming home at 11pm, there were people smoking weed in front of my door and one guy was pissing against the building close to my door. I went inside and everyone minded their own business.

Yeah those are not the nicest of experiences, however I'm rewarded every day by incredible access to art & culture (and amazing music gigs I can walk to by foot) and -- plainly -- I love people who step outside normalcy in terms of how they dress & express themselves. It's fun to see and makes me push my own boundaries :)

EDIT: Shoreditch is by now also an incredibly safe & affluent/expensive area. Never once have I felt threatened here, I feel safe carrying my phone on me at all times of day/night. This might be different in the cheaper-but-also-hipster areas of Hackney like Dalston.