(July 13 – 17:00 ET) – Credit Suisse First Boston has filed a US$1 million lawsuit against 11 individuals whom it accuses of defaming the firm and one of its analysts in the Yahoo message boards.

The messages concern Elan, an Irish pharmaceutical company. The suit reportedly claims that the defendants posted messages that contained false and defamatory statements about CSFB and one of its research analysts, David Maris.

Maris has apparently been ridiculed in the Elan chatroom for his opinions on Elan, which he rates a “hold”. Streetadvisor says this lawsuit will be closely watched because of its possible impact on message boards and online chat. It believes the lawsuit is frivolous and should be dismissed.