Images of CMEs with white light coronagraphs, highlighting the problems associated with CME definition. The top row shows two images of CMEs from (a) LASCO/C2 (standard background subtracted) and (b) STEREO-A/COR2 (running-difference); these are universally accepted as CMEs by the scientific community. The bottom row shows LASCO/C2 running difference images of narrow ejecta over which the community is divided as to whether to identify them as CMEs. Both images are from the same day (4 April 1999), but the one shown in panel (c) is identified as a CME in the widely used CDAW catalog, while the two shown in panel (d) are not. The author speculates that, in this case, the decision for CME identification at the discretion of the observer.