The article "Mystic Pizza Sues Pennsylvania's Mystic Pizzeria for Trademark Infringement," published in the Hartford Courant in March 2019, tells of a lawsuit for trademark infringement filed by Mystic Pizza, a small chain of restaurants in Connecticut, against Mystic Pizzeria, a restaurant in Pennsylvania. This makes the plaintiffs in the lawsuit Christos and John Zelepos, the owners of Mystic Pizza. The defendant would be Antonio Marques, who is listed as the owner of Mystic Pizzeria in the article. The last line of the article makes clear where the lawsuit was filed and what the plaintiffs are demanding:
The lawsuit, filed Thursday in a federal court in Philadelphia, seeks a court order against the pizzeria's use of the Mystic Pizza name and unspecified damages.
So, the lawsuit is all about the name Mystic Pizzeria being so similar to the name Mystic Pizza, which is a trademarked name, and the fact that the plaintiff thinks that the defendant deliberately made the name of his pizzeria sound like Mystic Pizza so he could profit off the similarity. The name Mystic Pizza became famous when the movie of the same name starring Julia Roberts came out in 1988. According to the article, Mystic Pizzeria opened several years after this time, so it is possible that the owner had Mystic Pizza's popularity in mind when he named his restaurant.
According to the US Patent and Trademark Office, or USPTO, "a trademark is a brand name" which is "to be used to identify and distinguish the goods/services of one seller or provider from those of others." The USPTO states that the registration of a trademark is not mandatory, but registration makes it easier to prove "exclusive right to use the mark." The article implies that Mystic Pizza's trademark was in fact registered. This is what the USPTO says about infringement:
To support a trademark infringement claim in court, a plaintiff must prove that it owns a valid mark, that it has priority (its rights in the mark(s) are "senior" to the defendant's), and that the defendant's mark is likely to cause confusion in the minds of consumers about the source or sponsorship of the goods or services offered under the parties' marks.
Trademark owners can also "claim trademark dilution," which means that another business's use of a similar mark might diminish the value of the trademark. Cybersquatting is similar to trademark infringement, but it takes place on the internet.
It is up to your personal opinion whether Mystic Pizza will win the suit, but a couple of major examples of trademark litigation might help. When Steve Jobs chose Apple Computer for the name of his company, Apple Corps, the music business founded by the Beatles, sued for trademark infringement. At first, the case was settled when Apple Computer promised to stay out of the music business, but later it took over all trademarks related to the word Apple and licensed the name to Apple Corps. Recently, Variety Stores sued Walmart over the use of its trademarked name "Backyard," and Walmart was forced to pay almost $100 million in damages. It is possible that a court might find in favor of Mystic Pizza, and if so, since Mystic Pizzeria has been using the name for over 25 years, it might have to pay a significant amount in damages.