I'm not a lawyer either, but I doubt that clause has much effect, if any. The DMCA defines "effective technological measure" as follows: > [A] technological m

I'm not a lawyer either, but I doubt that clause has much effect, if any. The DMCA defines "effective technological measure" as follows: > [A] technological measure “effectively controls access to a work” if the measure, 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. This seems like an objective metric, not something the copyright holder can arbitrarily "deem". However, in the usual case people worry about, where a user is "circumventing" by modifying software on their own device, one could argue that given the "Installation Information" clauses and the other parts of the GPLv3 aimed at ensuring the user has the ability to modify the software, it does not "in the ordinary course of its operation" require permission from the copyright holder. The "no covered work shall be deemed" clause could be seen to clarify intent. There are other cases, like if the GPL software was, say, a web server that someone had configured to password protect files they had copyright over, and a hacker bypassed the password protection. This would normally be covered by the CFAA and other hacking statutes, but the DMCA could apply too. In this case, the GPL's "waive any legal power to forbid circumvention" clause wouldn't apply because the hacking wouldn't be "effected by exercising rights under this License with respect to the covered work". But if the "no covered work shall be deemed" clause is effective, it would close off using 1201 against the hacker anyway...