Diana Simpson is a senior attorney with the Institute for Justice. She joined the Institute’s headquarters office in 2013 after working as a constitutional law fellow in the Arizona office.
Diana litigates to protect private property and other individual rights, with a particular interest in challenging irrational zoning decisions and abusive fines and fees practices. For instance, she represented a homeless shelter after a North Carolina town invoked bogus reasons to prohibit it from opening. The team obtained a federal court victory recognizing that the government violated the Constitution by irrationally denying the shelter its needed permit to open. She currently represents a Texas auto mechanic who faces an impossible-to-comply-with minimum parking requirement. And she is lead attorney in a lawsuit against the City of Chicago challenging its impound system, which imposes excessive fines and harsh fees on tens of thousands of Chicago residents and visitors each year. Beyond these cases, she has represented many other Americans in their fight to pursue their dreams.
Diana’s work has been featured by outlets including The Economist, The Wall Street Journal, National Public Radio’s 1A, The New York Times, and many others nationwide.
Diana's Cases
Code Enforcement | Fines and Fees | Private Property | Private Solutions to Public Problems | Zoning Justice Project
Albuquerque Bookstore Owner Partners with IJ to Defend Right to Provide Safe, Private Shelter
Gil Kerley, owner of Quirky Used Books & More in Albuquerque, New Mexico, sought to address the city’s worsening homelessness crisis by providing a safe and private space for homeless people to sleep on…
Eminent Domain | Private Property
Stiffed by a Pipeline Company Wielding Eminent Domain, Plains Ranchers Appeal to U.S. Supreme Court
North Dakota ranchers fought a pipeline company with eminent domain power for the fair value of their land. But an appeals court said the company did not have to pay the ranchers' attorney fees. That…
Woman Challenges Arizona City's Ban on Feeding People for "Charitable Purposes"
Norma Thornton was arrested for feeding the hungry in Bullhead City Community Park. Now, Norma has teamed up with IJ to fight back against Bullhead's law criminalizing charitable sharing in federal court.
Code Enforcement | Fines and Fees | Private Property
Homeowner Fights Back Against NYC's "Unreviewable" Fines System
Serafim Katergaris was forced to pay $1,000 to the New York Department of Buildings (DOB) for a code violation he did not commit, did not know about and had no chance to challenge. Now, he's…
Economic Liberty | Private Property | Small and Home-Based Business | Zoning Justice Project
Mechanic Challenges City of Pasadena's Mandatory Parking Minimum
Azael Sepulveda recently purchased a new mechanic shop, but the city of Pasadena will not let him open until he provides 28 parking spaces, which he does not need. Azael has partnered with IJ to…
Marcus & Millichap Real Estate Investment Services of Nevada, Inc. v. Chandra
In an appeal filed in February 2021, the Institute for Justice is asking the U.S. Supreme Court to examine the question of whether federal judges have unfettered discretion to unilaterally inject their own arguments or…
Fines and Fees | Private Property
New York Permit Fines
Joe Corsini keeps a pigeon coop on the roof of his home, like many other New Yorkers. The city’s Department of Buildings saddled him with thousands of dollars in fines for not having a license…
Private Property | Private Solutions to Public Problems | Right to Shelter | Zoning Justice Project
North Carolina Shelter Sues for Right to Offer Private Charity on Private Property
The town of North Wilkesboro, North Carolina attempted to block the only homeless shelter in the county from opening its doors at a new location, relying on bogus claims that the shelter would be “unharmonious”…
4th Amendment Project | Fines and Fees | Private Property
The Windy City Tows the Cars of Innocent People and Holds Them for Ransom
Chicago is towing the cars of innocent people and holding them for ransom. Victims of this unjust system are taking a stand, with IJ’s help, and calling for an end to this impound racket.
Other Property Rights Abuses | Private Property | Private Solutions to Public Problems | Right to Shelter
Akron Homeless Advocate Sues for Right to Shelter the Homeless
Sage Lewis is using his commercial property to build a community for those experiencing homelessness, with the hope of helping them transition from the streets to permanent housing. The city of Akron is attempting to…
Economic Liberty | Occupational Licensing
Animal Massage Therapists Now Free to Practice Their Craft in Arizona
Massage therapists do not need a medical degree to massage humans, but entrepreneurs who want to massage animals in Arizona must spend hundreds of thousands of dollars to attend four years of veterinary school where…
Arizona Citizen Files First Amendment Lawsuit Challenging Speech Regulations
Arizona wants to bar people from joining together to protest local ballot measures without first registering with the government.
Private Property | Rental Caps
Slamming the Door on Rental Bans: Winona Homeowners Stand Up for Their Property Rights
Government officials in Winona, Minn., are imposing a restriction on the number of homeowners who can rent out their properties, harming both homeowners and renters alike. Not only is this policy unwise, it is also…
Protecting Citizen Speech: Lawsuit Challenging Constitutionality of Mississippi Campaign Finance Regulations Continues Nationwide Campaign
Thanks to Mississippi’s burdensome campaign finance laws, groups of concerned citizens need more than just their opinions to speak about politics. They also need a lawyer.
Diana's Research & Reports
Civil Forfeiture | Private Property
Arizona’s Profit Incentive in Civil Forfeiture
Arizona’s civil forfeiture laws need to be reformed. In the upside-down world of civil forfeiture, police and prosecutors can seize and keep cash and property that was allegedly involved in criminal activity—without ever proving a…
Diana's Amicus Briefs
Carousel Farms v. Woodcrest Homes
Colorado Supreme Court
Center for Competitive Politics v. Harris
Supreme Court of the United States
Diana's News, Articles & Publications
Diana's Podcasts
June 23, 2026
Unpublished Opinions 25 | Pulling Up the Ladder
With guest host Patrick Jaicomo, he and IJ’s Anya Bidwell and Diana Simpson conspire on how best to keep the competition out of their guild. […]
Listen NowJune 12, 2026
Short Circuit 432 | Moth-Eaten Precedent
A wild, and tragic, story from the Fifth Circuit with a bit of good (yet confusing) news at the end. IJ’s Diana Simpson tells us […]
Listen NowSeptember 30, 2025
Unpublished Opinions 18 | Picking Favorites
Constitution Day might have been September 17, but Diana, Patrick, and John are still celebrating. From the insight that rights come before—not from—the government, to […]
Listen NowJuly 02, 2025
Unpublished Opinions 16 | Rings of a Hoary Oak Tree
A new edition of everyone’s favorite legal grimoire has dropped, and John Wrench convenes Sam Gedge and Diana Simpson to ask the hard questions: Is […]
Listen NowJune 29, 2021
Cities Caught Extracting Millions From Residents Through Fines and Fees Traps
In Episode 30 of Deep Dive, we talked about how fines for harmless property code violations could snowball into six-figure debt. All too often, municipalities […]
Listen NowMay 24, 2021
This Florida Woman Got a $100,000 Fine for Parking in Her Own Driveway
How Trivial Code Violations Can Lead to Financial Ruin—And How to Fight Back
After Sandy Martinez got a ticket from Lantana, Florida, for parking her car with its wheels slightly outside her driveway and on the grass in […]
Listen NowDecember 28, 2020
Property Rights and Homeless Shelters—What Has the Supreme Court Said?
How one local government board is trying to stop people from helping the homeless—and what the law says about whether they can
The Catherine H. Barber Memorial Homeless Shelter is the only option for people experiencing temporary homelessness in all of Wilkes County, North Carolina. It’s been […]
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