Taken from http://www.chillingeffects.org/anticircumvention/faq.cgi which can be found from the link provided by Kasz216:
"Question: What are technological protection measures?
Answer: Technological protection systems are already in place in DVDs, eBooks, video game consoles, robotic toys, Internet streaming, and password-protected sections of web sites. The fact that a digital protection may be really weak and easy to circumvent has not prevented courts from applying this law to punish those who bypass them.(Bolded for emphasis)
The DMCA defines an access control mechanism as a measure which "in the ordinary course of its operation, requires the application of information, or a process or a treatment, with the authority of the copyright owner, to gain access to the work." [1201(a)(3)(B)] An access control is a technology, like a password or encryption that controls who or what is able to interact with the copyrighted work. It is a violation of the DMCA to circumvent access controls, but it is also a violation to provide tools to others that circumvent access controls (including selling, distributing free of charge, and possibly even linking to a site with such technology ? or even the source code).(Bolded for emphasis)
The DMCA defines a copy control mechanism as a measure which, "in the ordinary course of its operation, prevents, restricts, or otherwise limits the exercise of a right of a copyright owner." [1201(b)(2)(B)]. Technological systems designed to protect against copyright infringement control whether the work can be copied, how many copies can be made, how long you can have possession of the work, etc. It is a violation of the DMCA to provide tools to others that circumvent copy controls [1201(b)], but it is not a violation of the DMCA to engage in the act of circumventing copy controls. Rather, the provision serves to buttress prohibitions against infringing activities of traditional copyright law."
Geohot found a way to circumvent "access controls" put in place on the PS3. He also posted the keys that would allow others to circumvent these "access controls". By posting the keys on his site for everyone who visted his site to see, he is possibly in violation of the DMCA.
