Felicity Huffman and Lori Loughlin are among 50 individuals facing federal charges in what investigators dubbed “Operation Varsity Blues,” a scheme in which wealthy parents allegedly cheated to help their children gain admittance to prestigious schools.

This is the largest college admissions scam ever prosecuted in the US. Federal prosecutors say the scheme involved cheating on standardized tests and bribing college coaches and school officials to accept students as college athletes, even if the student had never played that sport. William Rick Singer, CEO of a college admissions prep company called The Key, organized everything. Singer pleaded guilty to four charges Tuesday.

“There were essentially two kinds of fraud that Singer was selling,” US Attorney Andrew Lelling said.  “One was to cheat on the SAT or ACT, and the other was to use his connections with Division I coaches and use bribes to get these parents’ kids into school with fake athletic credentials.”

Loughlin, known to the world as Aunt Becky on “Full House,” is charged with conspiracy to commit mail fraud and honest services mail fraud. Her husband Mossimo Giannulli allegedly paid bribes up to $500,000 in exchange for their two daughters to be designated as recruits to the USC crew team, though they did not participate in crew, according to court filings obtained by CNN. The couple each received a million dollar secured bond.

Huffman, who garnered fame on “Desperate Housewives,” was arrested in Los Angeles Tuesday on charges of felony conspiracy to commit mail fraud and honest services mail fraud. She also appeared in federal court Tuesday, where the judge imposed a $250,000 bond. Allegedly she paid $15,000 to an organization that facilitated additional time and corrected answers on her daughter’s SAT exam.

Giannulli, Laughlin and Huffman were recorded on calls with a cooperating witness, the indictment stated.

“For every student admitted through fraud, an honest, genuinely talented student was rejected,” Lelling said.