Contact
Joey's Laundry listed under the Eat section above has internet for a fee, and the Main Library listed under the Architecture section above has free internet facilities. Other places include:
24fps Cafe
Standard internet cafe, these guys have free wi-fi and desktops if you don't have your own laptop. They also serve beer too and make a decent panini to go with your coffee.
The Tenderloin is one of San Francisco's lowest income neighborhoods and has all the socio-economic problems that stem from this including crime, homelessness, and drug addiction. In particular there is a lot of violent street crime like assault and theft. Parts of the Tenderloin are considered the most dangerous areas in San Francisco, with the exception of Hunter's Point and possibly a few areas in the Mission such as Mission between 16th and 17th Sts. Turk St and Taylor St might be considered the heart of the "true" Tenderloin; the sidewalks teem at all hours with the homeless, people openly selling crack or heroin, derelicts, hustlers, and the mentally ill. This area spills directly into Mission St on the other side of Market St; Mission St between 8th and 5th St may be considered part of this truly seedy "core Tenderloin" area. Travelers should be aware of their environment and take an appropriate amount of care. The area is lively and safe until about 2AM when the bars close; after that, it does get sketchy, and is best avoided by travelers walking alone.