According to reports, DC Comics, a unit of Time Warner’s Warner Bros., has filed a lawsuit against LA attorney Marc Toberoff in an attempt to protect their rights to the "Superman" property, after failing to settle with the heirs of the "Superman" creators Toberoff represents:

Allegedly Toberoff provoked the Siegel, Shuster families to repudiate those agreements, enter into new contracts with his companies and seek to terminate DC’s "Superman" copyrights.
But Toberoff, the high-profile copyright lawyer repudiates all claims.
"Having lost repeatedly on the merits over the last five and a half years in 'Superman' litigation," said Toberoff, "Warner Bros. and their new attorney Dan Petrocelli have now launched a libelous personal attack against me and my clients."