GFW is not perfect, however. Some Chinese technical professionals can bypass it with a variety of methods and/or tools. An arms race between censorship and circumvention has been going on for years, and GFW has caused collateral damage along the way.
VPN (virtual private network) and SSH (secure shell) are the most powerful and stable tools for bypassing all surveillance technologies, although the basic ideas are the same as with the aforementioned tools: proxies and encrypted channels. The only difference is that VPN and SSH depend on a private host (or virtual host) or an account outside of China, instead of open, free proxies. Only technical professionals are able to set up such hosts or accounts, and most of them are not free. Commercial or public VPN services will be blocked by IP address and/or domain names if they are popular enough. In fact, the domain names *vpn.* are all blocked (such as vpn.com, vpn.net, vpn.org, vpn.info, vpn.me, vpn.us, vpn.co).