In 1969, Jack Masquelier, a professor of pharmacology, discovered a chemical antioxidant made from the bark of a French pine tree. The substance supposedly assists in nutritional distribution and blood circulation. Horphag Research, Ltd., began to sell the product under the name Pycnogenol, which Horphag registered as a trademark in 1993. Pycnogenol became one of the fifteen best-selling herbal supplements in the United States. In 1999, through the Web site healthierlife.com, Larry Garcia began to sell Masquelier’s Original OPCs, a supplement derived from grape pits. Claiming that this product was the “true Pycnogenol,” Garcia used the mark as a meta tag and a generic term, attributing the results of research on Horphag’s product to Masquelier’s and altering quotations from scientific literature to substitute the name of Masquelier’s product for Horphag’s. Customers who purchased Garcia’s product contacted Horphag about it, only to learn that they had not bought Horphag’s product. Others called Horphag to ask whether Garcia “was selling . . . real Pycnogenol.” Horphag filed a suit in a federal district court against Garcia, alleging, among other things, that he was diluting Horphag’s mark. What is trademark dilution? Did it occur here? Explain.