Music publishers are staging a press conference in Washington on Monday to announce that they have targeted 50 websites with takedown notices for unlicensed song lyrics, arguing that they profit from the copyrighted works by collecting advertising revenue.

The National Music Publishers Assn. said that they will take legal action against sites that don’t remove the content.

“This is not a campaign against personal blogs, fan sites of the many websites that provide lyrics legally,” said David Israelite, the org’s president and CEO. “NMPA is targeting fifty sites that engage in blatant illegal behavior, which significantly impacts songwriters’ ability to make a living.”

The org claims that there are more than 5 million searches for “lyrics” on Google, and more than half of the page views are on unlicensed sites.

The org is working with David Lowery, lecturer at the University of Georgia’s Terry School of Business, on tracking sites. He notes that unlicensed lyric sites have been “largely overlooked” in the fight against piracy, in part because the public “doesn’t understand that this is a type of copyright infringement” and because of the notion that not a lot of money is at stake.

Lowery produced a list of the sites — ranking No. 1 is rapgenius.com — although he cautioned that it was still possible that some of those named are licensed but that they haven’t been able to locate those who would give such approvals. Others in the top 10 include lyricsmania.com, lyricstranslate.com, stlyrics.com, lyricsreg.com, lyricstime.com, lyrster,com, paroles-musique.com, kovideo.net, and songonlyrics.com.