The University of Houston was quick to sue for trademark infringement when a small local law school adopted the name "Houston College of Law."

But the university's fervor for protecting intellectual property went cold when a freelance photographer sought payment for an image used by the university in web and print publications without his permission.

The university not only used the image, a photo of the Houston skyline, but even removed the credit of the photographer, Jim Olive. When Olive sent a bill for $41,000 - $16,000 for its frequent use of the photo and $25,000 for stripping off the credit - the university, which has a $1.6 billion operating budget, refused to pay. And when Olive threatened the legal action, the university, a public institution, said it would claim sovereign immunity, a well-established legal principle that protects a state from getting sued.

"It doesn't seem quite fair, does it?" said Olive's lawyer, Dana Andrew LeJune. "You can't sue them, but they can sue others."

Olive's dispute with the University of Houston is another example of the lengths artists, writers and photographers must go to defend their rights in the age of the internet, when pictures, videos and stories are downloaded, posted, shared and otherwise reproduced with little attention or concern to copyright and other intellectual property laws.

They're not free

Freelance photographers and other creative professionals often earn their livings by licensing their work for use by others. The problem, Olive said, is people assume that anything online is in the public domain and they can use his photos as they wish. "They think: 'They're on the web. They're free,' " he said.

Olive, 71, specializes in skyline photos, which require him to rent a helicopter for as much as $2,500 an hour and sit sidesaddle out the open door as the chopper climbs high above the city's tallest buildings. Olive knows that many local organizations use his striking images of the city without his permission or payment, so he hires a scanning service to find out who is using his pictures and then checks to see if they have licensed the photos. If they haven't, Olive sends a letter warning that they are violating his copyright; most organizations pay up then.

Several months ago Olive followed the same routine in contacting the University of Houston about its use of his aerial photos in marketing materials, including a photo of Houston's skyline that the university provided to a national magazine for a story about the school's academic ranking. The university used the same skyline photo to advertise economic forecasting luncheons sponsored by its Bauer College of Business.

When the letter and request for payment didn't work, Oliver threatened legal action, only to learn that the university would claim sovereign immunity. In order to take the university to court, he would have to convince the Texas Legislature to pass a bill allowing him to sue.

In August, the University of Houston offered Olive a $2,500 settlement, according to a copy of the offer letter from University associate general counsel Eric Bentley. Olive turned that down.

Bentley declined to comment, referring questions to Michael Rosen, the university's executive director of media relations. Rosen said the university would not comment on an ongoing legal matter.

During this period, the university sued the South Texas College of Law for changing its name to the Houston College of Law and adopting similar red and white school colors. The University of Houston won a preliminary injunction last month, but U.S. District Judge Keith Ellison has not issued an order requiring any specific changes by the law school.

For now, the Houston College of Law continues to use the name, although it added a note on its website that it is not affiliated with the University of Houston. The law school declined to comment.

Steven Mitby, a Houston lawyer who specializes in intellectual property, said an institution like the University of Houston, which has an office to license its logo, as well as another to license technology and other intellectual property developed by its faculty, would be sensitive to the rights of others. He added that government institutions should not be above the law.

"Your ability to protect your property shouldn't depend on who is trying to steal it," he said.

If this were a different type of case, say, if Olive were hit by a university- owned vehicle, he could sue the university in state district court. Or if the university wanted to take real estate Olive owned to expand its campus, he would have a constitutional right to file a claim in court.

A possible opening

There may be an opening for Olive and others who have run up against similar sovereign immunity claims involving state institutions. Last year, the U.S. Supreme Court sided with raisin farmers who argued they shouldn't be forced to give up part of their crop each year to the government under a program designed to maintain price stability for agricultural products.

The court agreed with the farmers who claimed their raisins were personal property and protected by the same constitutional principle that protects real estate owners.

Some scholars have suggested the same argument can be used for patents, trademarks and copyrights, said Matthew Festa, a law professor at the Houston College of Law who specializes in land use and state and local government. If courts someday agree, he said, government agencies would have to pay for creative works much like they pay for land.

But Festa and other legal scholars will have to wait for another case to test the raisin argument. With little chance of winning his sovereign immunity claim, Olive doesn't see much reason to pay lawyers to litigate a case he seems likely to lose.