We claim the ornamental design for a storage device for electronic media, as shown and described.
FIG. 1 is a top, front and right side perspective view of the new design;
FIG. 2 is a top view thereof;
FIG. 3 is a left side view thereof, the right side being a mirror image;
FIG. 4 is a front side view thereof, the rear side being a mirror image; and,
FIG. 5 is a bottom view thereof.
The broken lines disclaiming the compartments in FIG. 2 are for the purpose of illustrating the environment of the design only and form no part of the claimed design.