ny_cable_guy writes "The following letter went out to all of Nielsen's clients this morning: 'Working together, Nielsen Media Research and TiVo have developed software that will enable the extraction of tuning, recording and playback information from TiVo's PVR system. TiVo has downloaded this new software as part of a normal system upgrade via phone lines to existing TiVo subscribers across the country. This software would be used only by Nielsen Media Research to retrieve data from sample households, and only with permission from the household, as is the case with all homes in our samples. It is otherwise inactive in non-Nielsen homes.' The full letter has been reprinted here on netWert."