For decades, people have been using lawsuits to retaliate against critics and deter scrutiny. They are called SLAPPs, strategic lawsuits against public participation, and they can financially cripple and ultimately silence their targets.

Most states have passed anti-SLAPP laws to help those truly being targeted for their public expression fight back. Think of it as an emergency appeal to a judge, a plea to the court to stop a meritless or malicious case from moving forward before a litigant is forced to spend significant resources defending themselves.

Anti-SLAPP laws have now been passed in most states.
Year anti-SLAPP legislation took effect by state
*Note: Washington and Minnesota were among the first states to pass an anti-SLAPP law. They were later invalidated, but both states then adopted the Uniform Public Expression Protection Act (UPEPA). South Dakota signed UPEPA into law in March 2026, but it doesn’t take effect until July.

But those laws vary in quality from state to state, and several states have no anti-SLAPP protections at all. Federal legislation, meanwhile, has remained elusive, hampered in part by a dearth of reliable data on the scope of the problem. Cases are scattered throughout state and federal court dockets, and opportunistic litigants can go “forum shopping” for jurisdictions with weak or non-existent protections. Multiple outlets have reported an increase in malicious lawsuits – but unlike in Europe – there is currently no reliable method for tracking and cataloguing this form of legal harassment in the United States.

The SLAPP Back Initiative aims to further understand the scale of this issue by building the country’s first comprehensive national database of SLAPP-related cases. To date, our team has found 16,094 unique citations to anti-SLAPP statutes across 10,257 individual cases, appearing in 209 state and federal jurisdictions since 1994, when the first anti-SLAPP decision recorded in Westlaw was filed in Washington state.

SLAPP-related cases appear across the country, but they are most prevalent in California, Texas, and federal courts.
Total historic cases citing anti-SLAPP statutes, by jurisdiction

As state-by-state anti-SLAPP laws have proliferated to combat SLAPPs, they have grown increasingly visible.

In 1992, California became one of the first states to pass strong anti-SLAPP legislation, and the state consistently represents slightly less than half of all SLAPP-related cases nationwide every year. Federal cases, meanwhile, have steadily increased over time, particularly with the introduction of the Uniform Public Expression Protection Act (UPEPA) in 2020. Texas had no anti-SLAPP protections until 2011, but by 2020, Texas had more cases citing anti-SLAPP statutes than any other state in the country.

Dominating SLAPP-related cases nationwide, California, Texas, and federal courts saw different trends over time as new laws were introduced.
Total count of cases citing anti-SLAPP statutes, by year of decision and jurisdiction, 1994 to present

Our analysis is currently limited to cases involving anti-SLAPP motions with decisions filed in 2024, and we should note: It is an undercount. There are several reasons a relevant case might not appear in our database, including if the case was not decided in 2024, if a judge did not reference a specific anti-SLAPP statute in a decision, or if the case was not reported to and recorded by Westlaw.

But we intend to expand the database to include the more than 10,000 lawsuits in which a judge cited an anti-SLAPP statute in the more than three decades of legal history around this issue. And we will aim to make this dataset more robust and accurate by scraping other legal databases, surveying the public and scouring media reports, all as we track new cases that emerge in 2025 and beyond.

Get in touch with us! Send us an email at slappback@nyu.edu for press inquiries, partnership requests, or any questions about our project.
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