The same day that she helped to dedicate an exhibit at Cleveland's airport recognizing the city as the place of Superman's creation, Jerry Siegel's daughter issued a letter to fans recounting her family's fight to reclaim a portion of the Man of Steel copyright, and criticizing the tactics used by Warner Bros. and DC Comics in the increasingly bitter legal battle.

Characterizing their 15-year crusade as "my family's David and Goliath struggle against Warner Bros.," Laura Siegel Larson writes, "My father, Jerry Siegel, co-created Superman as the 'champion of the oppressed ... sworn to devote his existence to helping those in need!' But sadly his dying wish, for his family to regain his rightful share of Superman, has become a cautionary tale for writers and artists everywhere."

A federal judge ruled in 2008 that the family had succeeded in recapturing that share of the first Superman story in Action Comics #1 through a provision of the U.S. Copyright Act (the scope of the decision is on appeal), paving the way for the estate of Joe Shuster to do the same in 2013, effectively stripping DC of some of the defining elements of the Man of Steel, including his secret identity, his origin, his costume and Lois Lane. DC fired back in 2010, suing to force Marc Toberoff to resign as the Siegel attorney, claiming he enticed the heirs to walk away from a $3 million deal that would've permitted the company to retain control of Superman and stands to gain controlling interest in the property. DC is also asking a court to block the Shuster estate from reclaiming its stake, arguing the family relinquished all claims to Superman in 1992 in exchange for “more than $600,000 and other benefits,” including payment of Shuster’s debts following his death earlier that year and a $25,000 annual pension for his sister Jean Peavy.

Siegel Larson's letter, first published by The Hollywood Reporter, arrived on the heels of a DC motion filed Wednesday in the Shuster case accusing Toberoff of, among other things, concealing evidence.

"Warner has spent about $35 million dollars on corporate lawyers to fight my family and the Shusters instead of investing in a fair settlement," she writes. "The very attorneys who are lining their pockets with millions in fees accuse my attorney of profiteering when, in fact, Marc has not received one cent since he filed the first Superman case for us in 2004, and has advanced enormous sums out of his own pocket on our behalf. Unlike Warner's highly paid attorneys, Marc Toberoff will not be compensated unless and until we prevail."

Siegel Larson's mother Joanne Siegel wrote to  Time Warner Chairman Jeffrey L. Bewkes shortly before her death in February 2011 pleading for an end to the company's “mean-spirited tactics” and asking for a resolution to the legal feud. Read Siegel Larson's full letter below.