This constitutional source says that the “monopoly” granted must be temporary, and that the restraints (under copyright and patent law) should serve a particular purpose, the promotion of knowledge and art. Still, over the years, the duration of those “temporary restraints” (exclusive rights) has been increasing.
It is also not apparent that the constitutional purpose is a consistently observed guiding principle. Some argue there is too fierce a trend currently toward expanding copyright and its enforcement. At the same time, increased copyright vigilance has been regarded by others as a necessity given the ready distribution and easy duplication afforded by digital technology.
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