Can Font Software released under the OFL be subject to URL-based access restrictions methods or DRM mechanisms?
Yes, but these issues are out-of-scope for the OFL. The license itself neither encourages their use nor prohibits them since such mechanisms are not implemented in the components of the Font Software but through external software. Such restrictions are put in place for many different purposes corresponding to various usage scenarios. One common example is to limit potentially dangerous cross-site scripting attacks. However, in the spirit of libre/open fonts and unrestricted writing systems, we strongly encourage open sharing and reuse of OFL fonts, and the establishment of an environment where such restrictions are unnecessary. Note that whether you wish to use such mechanisms or you prefer not to, you must still abide by the rules set forth by the OFL when using fonts released by their authors under this license. Derivative fonts must be licensed under the OFL, even if they are part of a service for which you charge fees and/or for which access to source code is restricted. You may no
