Houston-based Texas EquuSearch has kept its promise to sue Casey Anthony.  The lawsuit says Anthony knew her daughter, Caylee Anthony, wasn't missing, and that she lied to the organization as its volunteers spent months looking for the 2-year-old.

The lawsuit, seeking damages for fraud and unjust enrichment, was filed Tuesday in Orange County, Florida, where more than 4,200 EquuSearch volunteers from 13 states dedicated services in the summer and fall of 2008 to find Caylee.

EquuSearch spent more than $100,000 on motel rooms, rented vehicles and other expenses that consumed 40 percent of the organization's annual budget.  The suit demands full repayment for services rendered based on "lies, omissions and deceptions."

The lawsuit claims the Florida search consumed 40 percent of EquuSearch's annual budget, and forced the group to turn away requests from other families to look for their missing loved ones.

If the lawsuit is successful, it's not clear where Anthony will get the money to repay EquuSearch.  The plaintiff could demand payment from whatever money Anthony makes from selling book and movie rights.