Resident here. If you live or work here, I think the best advice is to not be naive. Trust your instincts. Don't assume that a transitional neighborhood (where the houses are quaint but well-kept) is safe. Don't walk around with your iPhone out if you see other people watching you, etc. Living in Oakland can have its attractions, but if you're at the wrong place at the wrong time, you might be ganked, so keep tabs on your surroundings.