For 30 years, he was in private practice, concentrating in complex business and commercial litigation, including class actions on behalf of investors, consumers and victims of environmental disasters.

Professor Jacobsen also is a businessman who co-owns successful businesses in the sports and entertainment industries. He was a founding partner of the Wilmington Blue Rocks, a single “A” minor league professional baseball club affiliated with the Washington Nationals who play in a 6,500 muti-purpose stadium adjacent to Interstate 95 in Wilmington, Delaware. He provides legal advisory and consulting services to professional athletes on sponsorship and endorsement deals, appearances and other marketing activities. He also has organized their charitable foundations and provided financial and other support to their non-profit organizations. Among his former clients are Phillies All Star Shane Victorino, former Philadelphia Eagles quarterback Michael Vick, NBA basketball legend Julius “Dr. J” Erving and other notable professional athletes.

A sought-after guest speaker and prolific author of articles and commentary, Professor Jacobsen is a frequent lecturer and seminar participant on topics involving sports law, trial practice and procedure and complex commercial litigation. In May 2026, he delivered a lextio magistralis (Master Lecture) on comparative International Sports Law to students, faculty and lawyers at the Universita di Padova in Italy, which awarded him the Osella medal for his “foresight, global perspective and pursuit of justice through law.” A nationally recognized expert on “name, image and likeness” (NIL) in college sports, Professor Jacobsen has organized and served on NIL panels for the American Bar Association in Las Vegas in October 2025, the Philadelphia Bar Association in June 2025 and March 2022, IP Philadelphia in March 2026 and many other programs and symposia.

Drawing of his expertise in college athletics, Professor Jacobsen help organize and present the Temple Law Review Symposium “A House Divided: A Legal and Practical Discussion of the Changing Landscape of College Athletics” in October 2024, which featured elite panelists from across the country and drew a record attendance of 300 lawyers, educators and college administrators in person and online.

In 2026 and 2022, Professor Jacobsen taught summer semesters in International Sports Law to law students from multiple U.S. law schools at Temple’s campus in Rome, Italy. In 2015 and 2016, he was a Visiting Professor and Lecturer at the National Taiwan University College of Law, where he delivered keynote speeches in International Sports Law and taught classes on the subject. He also addressed committees of Taiwan’s National Congress (the legislative Yuan) on the regulation of professional sports and met with owners of professional baseball teams and representatives of the players’ union there to compare organizational and governance structures with that of Major League Baseball in the United States.

Professor Jacobsen was a regular faculty member of the National institute for Trial Advocacy (NITA) for its regional trial practice programs and was a featured panelist for CLE International at its annual conference in Chicago on consumer class actions. Other past programs include Mealey’s “Emerging Drug Conference—Litigation Issues” in New Orleans; ALI-ABA Course Seminar in Washington, D.C on the “Trial of a Securities Case;” the Villanova Law Review Symposium of “Sports Franchise Relocation;” the Penn Law School Symposium on gambling in sports; the Practicing Law Institute Program in New York on “False Advertising and Commercial Speech—Private Consumer Actions and Remedies;” and the American Bar Association program in Williamsburg, Virginia on “Troubled Partnerships—Some Litigation Issues.” Professor Jacobsen lectures annual to lawyers enrolled in Temple Law’s LLM Program in Trial Advocacy and has made presentations to its Board of Visitors at both its Philadelphia and Rome campuses on legal issues in amateur and professional sports.

Professor Jacobsen's article  “A Tale of Two Circuits: Curbs on Legal Remedies for Exposure to Potentially Harmful Cell Phone Radiation Emissions,” was published in 2014 in Volume 10 of the Seton Hall Law School Circuit Review. His article " Rolling Back the 'Pink Tax': Dim Prospects for Eliminating Gender-based Price Discrimination in the Sale of Consumer Goods and Services " was published in the Spring 2018 edition of the California Western Law Review (Volume 54, No. 2). Professor Jacobsen's latest article " Leveling the Playing Field - U.S. Court Jurisdiction Over Disputes Between American Professional Athletes and Foreign Sports Teams ' was published in the Spring 2020 edition of the Villanova Sports Law Journal. His article " Navigating [the] Amazon: Liability of E-Commerce Companies for Defective Products Sold on their Websites " was published in Fall 2021 edition of the DePaul Law Review.

Professor Jacobsen is admitted to practice before the Supreme Court of Pennsylvania, the United States Supreme Court, the United States Court of Appeals for the Second Circuit, the United States Court of Appeals for the Third Circuit, the United States Court of Appeals for the Fifth Circuit, the United States Court of Appeals for the Seventh Circuit, the United States Court of Appeals for the Ninth Circuit, the United States Court of Appeals for the Eleventh Circuit, the United States District Court for the Eastern District of Pennsylvania, the United States District Court for the Northern District of California and the United States District Court for the District of Arizona. Mr. Jacobsen is a cum laude graduate of the Villanova University School of Law, where he was the Managing Editor of the Villanova Law Review and was elected to the Order of the Coif. 

In the consumer area, Mr. Jacobsen has represented the interests of policy owners of insurance companies and was successful in enjoining the proposed conversion of Provident Mutual Life Insurance Company to a mutual holding company which resulted in the distribution of $1.3 billion in stock to policy holders. Mr. Jacobsen served as lead class counsel in O’Keefe v. Mercedes Benz USA, 214 F.R.D. 266 (E.D.Pa. 2003), a national consumer class action in which $33 million in extended warranties and other benefits were obtained for owners of Mercedes vehicles. In his most recent jury trial, Mr. Jacobsen won a unanimous $4 Million verdict on behalf of automobile dealerships against their lender in Mente v. GMAC (E.D. Pa.).

Professor Jacobsen was lead counsel in a class action against medical insurers in which settlement benefits of $75 million were obtained for 7,000 doctors in Central Pennsylvania in Grider v. Keystone Health Plan Central, Inc., Civil Action No. 01-5641 (E.D. Pa.)

More recently, Mr. Jacobsen was lead counsel in a class action brought by commercial delivery companies against the City of New York over illegally issued parking tickets, in which a $14 million settlement was achieved for his clients. Lockman v. City of New York, 11-cv-1836 (E.D.N.Y.)

In the environmental field, Mr. Jacobsen served as Plaintiffs’ Counsel in such cases as Cook v. Rockwell, et al., No. 90-K-181 (D. Colo.), a class action on behalf of Colorado citizens residing in the vicinity of the Rocky Flats nuclear weapons facility, whose property values were diminished as a result of releases of radioactive plutonium and other environmental contaminants from the plant, and which resulted in a $554 million jury verdict.

In the area of securities litigation, Mr. Jacobsen has played a leadership role in the prosecution of the Petro-Lewis Securities Litigation, Civil Action No. 84-C-326 (D. Colo.), in which a settlement valued in excess of $137 million was recovered on behalf of shareholders and limited partners; in the Baldwin United SPDA Litigation, MDL No. 581 (S.D.N.Y.), in which a settlement of more than $170 million in cash and other benefits was obtained on behalf of purchasers of annuities; and in several other substantial securities class actions and derivative litigation.

Professor Jacobsen also has been responsible for establishing appellate precedents in the business litigation and class action areas.