Unions representing America’s professional athletes say they’re entitled to compensation from daily fantasy sports (DFS) operators, a stance that could extend to the country’s new legal betting environment.

On Friday, representatives of the player unions of all four major pro sports (MLB, NBA, NFL and NHL), plus Major League Soccer, the WNBA and the Women’s National Team Players Association filed an amicus curiae brief in the Indiana Supreme Court case involving DFS operators DraftKings and FanDuel.

The case was filed in 2016 by three college football players who argued that they were entitled to compensation for the use of their names, likeness and statistical data by DFS operators. An NFL wideout filed a similar case against FanDuel in Maryland in 2015.

The case centered on Indiana’s ‘right of publicity’ statute, but lower courts have determined that the DFS operators’ use of the players’ identities falls within the statute’s exceptions for ‘newsworthiness’ and ‘public interest.’ The athletes have appealed these rulings and now the pro player unions are adding their weight to the argument.