Licensors may request removal of attribution
In the 4.0 licenses, a user must remove attribution from a work at the creator's request to the extent it is reasonably practicable to do so. This is true whether the work is modified or unmodified. (See Section 3(a)(3) of CC 4.0 legal codes.)
All creative commons licenses, after 1.0 require attribution. However, legislation in many countries gives authors the right to control the use of their name in association with their works. Therefore, CC licenses require licensees to remove attribution to the creator at his or her request, where it would otherwise be required to include it. In 2.0, 2.5, and 3.0, credit must be removed from adaptations and collections, to the extent practicable, at the creator’s request. In 4.0, the creator may also request removal of credit from the unmodified work.