Officials from the Harvard Coop Book Store confront Crimson Reading Director Jon T. Staff V ’10 yesterday. Staff and two others, who were copying textbook ISBN numbers, were asked to leave by Coop officials but refused.

The Harvard Coop called police yesterday after three undergraduates collecting information for a student-run textbook-shopping Web site refused to leave the bookstore. The two Cambridge police officers who arrived allowed the students to continue copying down book identification numbers, which they did for two and a half hours before leaving on their own terms.

The Cambridge Police Department said its officers removed three or four males from the Coop’s third floor, where textbooks are sold, at a Coop official’s request after receiving a call from the store at 4:34 p.m. But a Crimson reporter and photographer present did not see anyone removed, and the three students collecting data for the Crimson Reading Web site also said they did not witness the police escorting anyone from the floor.

The tense afternoon at the venerable 125-year-old bookstore comes two days after the Coop reaffirmed a policy discouraging students from copying down book identification numbers. Students are able to go online and use those numbers, known as ISBNs, to find better deals for textbooks.

The year-old, student-run crimsonreading.org site allows Harvard students to find cheap textbooks at Internet booksellers by clicking on the courses they are taking. The Coop has argued that it owns intellectual property rights to the identification numbers for the books it stocks, which are organized by course on the third floor. Crimson Reading Director John T. Staff V ’10 insists the information is in the public domain.

Staff was at the Coop yesterday from about 4:30 until 7 p.m. Coop officials repeatedly asked Staff, Adam Goldenberg ’08, and Jarret A. Zafran ’09 to leave the floor, but the students refused.

A spokesman for the Cambridge police, James DeFrancesco, said that no crime was committed and no arrests were made.

Two Cambridge police officers arrived at the scene at about 5:30 p.m. They departed after talking to Coop officials, and Staff was able to continue copying down ISBNs.

Coop President Jerry P. Murphy ’73 did not return repeated requests for comment last night.

For Staff and Crimson Reading co-founder Tom D. Hadfield ’08, yesterday’s events represented a turning point for the fortunes of the Crimson Reading Web site, which will benefit from the 450 ISBNs that the three students collected yesterday. Staff said the site has recorded $23,000 in sales so far this semester by routing students to vendors such as Half.com and Amazon.com.

“Today’s incident proves that the Coop doesn’t believe its own propaganda about owning ISBN numbers,” Hadfield said. Hadfield and Goldenberg are both members of the Crimson editorial staff.

Hadfield added that he encourages all students to continue collecting textbook information from the books sold at the Coop if they wish to comparison-shop online themselves.

Staff said he expected to return to the Coop today. “As of now I plan to get more ISBNs,” he said.

But yesterday’s incident exposed a rift between Crimson Reading and its partner, the Undergraduate Council. UC President Ryan A. Petersen ’08, whose organization works with Crimson Reading to maintain the site and database, said that Crimson Reading should respect the Coop’s request that students not write down textbook information in the store.

“Crimson Reading will not be returning to the Coop now that they’ve made their policy clear,” Petersen said last night.

Responding to Petersen’s remarks, Staff questioned the UC president’s authority to determine whether Crimson Reading would be coming back to the Coop against Murphy’s wishes.

“Ryan has no authority to make that call,” said Staff, who is also a UC representative. “I’m the director of Crimson Reading, and I will be the decision-maker regarding its future along with Tom Hadfield.”

Staff also said that Crimson Reading’s renewed efforts at collecting textbook ISBNs from the Coop itself came after fresh assurances from several parties—including an intellectual property lawyer—that such actions were legal and not a violation of intellectual property laws, as the Coop has alleged.

Jonathan L. Zittrain, the director of Harvard Law School’s Berkman Center for Internet & Society, also said yesterday that Crimson Reading’s actions appeared to be legal.

“It’s hard to see [the ISBNs] as intellectual property,” Zittrain said in an interview. He said of the Coop’s policy: “It sort of takes the ‘co’ out of ‘Coop’ to do that. I’m sure the Coop isn’t interested in suing its patrons and it probably should just say that it welcomes the competition and welcomes students.”

—Aditi Balakrishna and Jamison A. Hill contributed to the reporting of this story.

—Staff writer Christian B. Flow can be reached at cflow@fas.harvard.edu.