Methods and apparatus are provided for making an optically readable media unreadable. The method includes steps of (a) providing the media with an optically activated mechanism that degrades the
reflectivity of a surface wherein information is encoded; (b) exposing the media to
optical radiation for reading out the information; and, during the step of exposing, (c) initiating the operation of the optically activated mechanism. In this embodiment the step of initiating includes steps of (d) generating
singlet oxygen in a layer disposed on the media; and (e) reacting the
singlet oxygen with a
metal-containing layer for oxidizing the surface of the
metal-containing layer, thereby degrading the
reflectivity of the surface. In a further aspect the optically activated mechanism causes a defocusing of a readout beam, thereby degrading reflection of the readout beam from a surface wherein information is encoded. In another embodiment the method deforms a surface of the layer resulting in readout beam aberration or in an inability to correctly stay on track. In another embodiment a portion of the surface is removed to the
atmosphere, such as by
evaporation of sublimation. In this embodiment a layer of the media is comprised of a volatile component and at least one other component. Removing at least some of volatile component by
evaporation or sublimation causes an increase in at least one of photoabsorption or scattering or
surface roughness with the remaining component, thereby rendering at least a portion of encoded information of the media unreadable, or affecting the tracking operation.