What does "brave the street" mean? is that an idiomatic expression?

It means go out into the street and face the dangers that are there. This expression is coming up in the news a lot these days as people go outside their houses (like in Iran or Libya) when it would be safer to stay inside.

I've also heard the expression "brave the stock market" in cases where the market is volatile and there are many chances of losing money. It would be safer NOT to invest at such a time, but people are taking chances anyways.