A new lawsuit has companies wondering: Who owns a Twitter account?

PhoneDog, a Web site that reviews mobile products and services, claims that it owns the rights to a Twitter account launched by a former employee.

While working as a product reviewer and video blogger for PhoneDog, Noah Kravitz signed up for a Twitter account with the handle, “@PhoneDog_Noah.” By the time Kravitz left the company, the account had more than 17,000 followers. Prior to leaving, Kravitz changed the name of the account to “@NoahKravitz.”

After freelancing for a period of time, Kravitz took a job with a PhoneDog competitor and continued to use the Twitter account.

PhoneDog responded with a lawsuit. The company argued that it provided to employees on a need to know basis confidential information, including passwords to PhoneDog’s Twitter accounts, including all @PhoneDog_NAME Twitter accounts used by PhoneDog’s employees.

The company further alleged that Kravitz had misappropriated trade secrets because the Twitter followers were the equivalent of a stolen customer list.

“The costs and resources invested by PhoneDog Media into growing its followers, fans and general brand awareness through social media are substantial and are considered property of PhoneDog Media LLC,” the company said in a statement to the New York Times.

Interestingly, PhoneDog’s complaint also attempted to put a specific monetary value on Twitter followers. Relying on “industry standards,” the company said that Kravitz owes it $2.50 per follower, or approximately $42,500 per month.

Kravitz’s actions were “designed to disrupt, and [have] in fact disrupted, PhoneDog’s economic relationships with its existing and prospective users,” according to the complaint.

In addition to compensatories – $340,000, or eight months of Kravitz’s use of the account at $42,500 per month – the suit seeks punitive damages and an injunction restraining Kravitz from using the Twitter account.

While the suit garnered publicity for its unusual premise, U.S. District Court Judge Maria-Elena James found it solid enough to deny Kravitz’s motion to dismiss.

PhoneDog specifically alleged “that a significant amount of its income is derived from advertisements on its website, and ‘advertisers pay for ad inventory on PhoneDog’s website for every 1,000 page views generated from users visiting PhoneDog’s website.’”

Kravitz’s conduct resulted in diminished traffic to the Web site via the Twitter account, PhoneDog claimed, which decreased the number of page views and discouraged advertisers from paying for ad inventory.

Therefore, Judge James said PhoneDog had established its economic relationships that suffered due to Kravitz’s actions.

She declined to dismiss the suit and allowed the case to move forward.

To read the complaint in PhoneDog v. Kravitz, click here.

To read the court’s order denying Kravitz’s motion to dismiss, click here.

Why it matters: The issues presented by the case – who owns a Twitter account, employer or employee, and what is the value of a Twitter follower? – are relevant for any company engaging in social media. If the case continues, it could define the ownership rights of companies using Twitter or Facebook for product or company branding.