There’s such a thing as too much of a good thing. James Green points out a good example in a letter to the editor today. The College of Charleston enhances the city with its vitality and scholarship. But the presence of students has encouraged some rental property owners to overfill apartments. That can have ill effects on already dense residential neighborhoods. Neighbors who have to compete for parking, cope with noise and deal with congestion know six students in a single apartment is too many.

And the law is clear: No more than four unrelated people are allowed to share a housing unit.

The penalty for a landlord who is guilty of allowing too many tenants in a unit can be $1,000. Tenants are required to reduce their numbers.

Tim Keane, director of Charleston’s Department of Planning, Preservation and Sustainability, said violations of the city’s law are common — 10 to 15 a year. The city, he says, relies largely on neighbors to report problems. And sometimes it can take some time to confirm when the law is being broken.

But, he says, the city does follow through on complaints, and judgments are made against lawbreaking landlords.

Mr. Green is correct that apartment problems are every day, not a few times a week, like crowds, air emissions and noise from cruise ships. The difference is that neighbors can report lawbreaking landlords and expect city action. Unfortunately, there is no municipal law restricting the cruise industry.