I think a big issue is that Oakland is way bigger than people think, especially geographically - it covers more land than SF - and there's a lot of diversity. Some regions are really bad. Some regions are ritzy. There's plenty of everything between. But the news doesn't differentiate well between the different parts of Oakland, so when you hear over and over that there was crime in Oakland and you're sufficiently unfamiliar with it that your model has it as an undifferentiated blob, and you think that blob is smaller than it is, of course you think anything about Oakland is scary.