We are traveling to San Francisco soon. Friends were telling us that they heard there is a lot of crime there. Is it safe to walk in the touristy parts at night? We will be staying at the Hotel Nikko, corner of Mason and O'Farrell which I know borders the "Tenderloin". Is it safe to walk back to our hotel at night, before 11 pm, but we definitely will be coming back after dark. Opinions please?