SAN FRANCISCO—A South Carolina media company's lawsuit against a former employee over allegedly stolen Twitter followers can proceed to trial, a federal judge ruled Monday.

Mount Pleasant, S.C.-based Phonedog L.L.C., an online publisher of consumer electronics reviews, claims a former California-based writer for the website, Noah Kravitz, stole more than 17,000 Twitter followers from the company when he resigned in 2010, according to documents filed in U.S. District Court for the Northern District of California in San Francisco in July.

When he resigned in October 2010, PhoneDog claims it asked Mr. Kravitz to turn over access to the Twitter account he had maintained on behalf of the company. Instead, Mr. Kravitz allegedly changed the account's online handle from a company-branded name to a personal one and continued using the account—initially to supplement his freelance writing, and later as full-time writer for a competing website.

In a motion to dismiss the lawsuit, attorneys for Mr. Kravitz argued that PhoneDog had not been able to establish that Mr. Kravitz's conduct directly disrupted economic relationships between the company and the Twitter followers, its advertisers or other media outlets.

U.S. Magistrate Judge Maria-Elena James on Monday rejected Mr. Kravitz’ motion, noting that the company had demonstrated that the decrease in traffic to its website generated by the loss of the Twitter followers would reasonably impact the company’s ability to sell ad space on its site.

“Based on these factual allegations, the Court is able to draw the reasonable inference that PhoneDog had an economic relationship with at least one third-party advertiser that was disrupted by Kravitz’s alleged conduct, causing it economic harm,” Judge James wrote in her decision.

In its suit, PhoneDog claims the Twitter followers are the legal equivalent of a client list, which would ordinarily be treated as protected and proprietary information.

Using industry standards, PhoneDog estimates the value of the lost Twitter followers at $42,500 per month, according to the lawsuit.

The company is seeking $340,000 from Mr. Kravitz to make up for the eight months of lost access that had accrued by the time of the lawsuit’s filing.