The American Civil Liberties Union (ACLU) filed a lawsuit in U.S. federal court on Wednesday challenging the constitutionality of an anti-hacking law, which it says prevents academics and others from collecting data to investigate whether online algorithms may be discriminatory.

The organization is representing Intercept publisher First Look Media’s nonprofit arm and researchers who are challenging the Computer Fraud and Abuse Act (CFAA).

The suit, Sandvig v Lynch, asks that the courts invalidate the law, which has been the basis for hacking and computer crime prosecutions since its enaction by Congress in 1986.

Courts have interpreted a provision of the CFAA prohibiting people from exceeding authorized access to a computer to include violations of website terms of service, the ACLU said.

Those same practices are used by researchers to test whether sites are, for example, more likely to show higher interest rate loan ads to people of color or show higher paying jobs to men who search employment listings.

Studies like these necessarily require researchers to create dummy online identities and record what content is served up to those identities.

“The discriminatory results are often the result of algorithms relying on “big data” analysis to classify people based on their web browsing habits or other information collected by data brokers — and then steer them towards various products or services,” said ACLU in a blog post.

The Computer Fraud and Abuse Act has been widely criticized in recent years by open internet advocates and civil libertarians, who say the 30-year-old statute is outdated, too sweeping and carries excessively harsh penalties that often target malign behavior.

Assistant Attorney General Leslie Caldwell has defended CFAA as the central law used to pursue malicious hackers, and said last year that prosecutors do not seek to use it against individuals engaging in “legitimate activity.”