One of the senators behind the law that requires President Bush and John Kerry to say "I approved this message" in their television and radio campaign ads wants to expand the provision to other media.

Sen. Ron Wyden (search), D-Ore., and Sen. Lindsey Graham (search), R-S.C., unveiled legislation Thursday that would require federal political candidates to take responsibility for the content of their print newspaper ads, bulk mail, e-mail messages, Web videos and prerecorded phone calls that directly refer to the candidate's opponent.

Wyden had worked with Sen. Dick Durbin (search), D-Ill., to get the TV and radio requirement enacted because they thought the public should know who is behind attack ads.

Their "Stand By Your Ad" provision went into effect last November, requiring candidates for federal office to appear in their paid television and radio ads, identify themselves and tell voters that they approved the message.

Since then, however, Wyden said candidates have learned how to "exploit the power of the Internet" and that "the meanest political messages" have appeared online where the "Stand By Your Ad" requirement doesn't apply.