In a ruling handed down Monday in San Francisco, US District Judge Charles Breyer refused the request of PadMapper, 3 Taps and other defendants to throw out a laundry list of claims by Craigslist, which is accusing the defendants of hacking, copyright infringement and more.

In the view of Craigslist, the newer companies are plundering data which it has collected and compiled at great effort. The defendants, meanwhile, say Craigslist is monopolizing data that belongs to users while offering an ugly, out-dated service. The lawsuit broke out last summer.

In a key part of Tuesday’s highly-technical decision, the judge examined whether Craigslist’s terms of service meant that users had given the site permission to use their ads as the basis for copyright lawsuits. The judge said Craigslist didn’t obtain such permission, except for a short period in the summer of 2012 when the site changed its terms of service — before backing down in the face of a popular backlash.

What this means is that Craigslist can rely on users’ ads to go forward with its copyright lawsuit, but only those ads written between July 16 and August 8, 2012. The judge also said said that Craigslist may have its own copyright over the way it has compiled the ads, though it will still have to prove that this compilation is an “original” artistic work.

The hacking portion of the decision, which is based on the federal Computer Fraud and Abuse Act and a similar law in California, is also nuanced. The judge wrote that the companies’ attempts to access Craigslist data after receiving cease-and-desist letters might be “unauthorized access” under the laws, but implicitly suggested that the laws are out of date.

The judge also gave Craigslist a minor victory by agreeing to shelve counter-claims from Padmapper and 3Taps over the monopoly issue. The defendants won their own minor victory when the judge threw out Craigslist’s conspiracy claims.

So what does all this mean? Monday’s decision is very preliminary and was about what can stay in the case — the real action will start at the summary judgment stage, likely later this year, where each side can try to win on a matter of law.

In the bigger picture, the case is important because it is helping to set the rules over the degree to which companies can treat data controlled by other firms as a public good.

This is just a short summary of a complex decision. If you want to get further into the weeds, here is a marked-up copy of the ruling itself:

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Lovely is a real estate rental listing company based in San Francisco that went nationwide this fall. It has an agreement with 3taps, the company locked in a legal battle with Craigslist over the ownership of that real estate data, but Lovely also works with landlords and property management companies to independently list available items and aggregate similar postings from across the web. And not surprisingly, compared to the antiquated Craigslist website, it’s well, pretty lovely to use. The company is launching a new iPhone app Wednesday that’s just one of many features modern renters demand.

Like many San Francisco residents, I eventually found my apartment in the city through Craiglist and a lot of luck. But in thinking about the problems with Craigslist – not being able to save listings, not being able to search by map or location, not being able to effectively sort by price or type of apartment — Lovely provides an excellent contrast, and I wish I’d had it available when I moved in May.

The site has all of these features Craigslist lacks and more, allowing users to sort their favorite listings, set alerts on properties they’re interested in, and contact landlords with a basic renter’s bio. Lovely looks most similar to Padmapper, since both sites begin with a map and let users narrow down their search by price and rental type. But the Lovely interface feels a little more modern than Padmapper, and when searching apartments in my neighborhood, it seemed Lovely had far more complete data than Padmapper did.

But if 3taps loses its legal battle with Craigslist and can’t provide that data anymore, could Lovely still prove useful? CEO and founder Blake Pierson said he thinks it can, since they’re working to create direct relationships with landlords and software companies that work with property management groups to post listings.

“Obviously they’re sorting stuff out,” Pierson said of 3taps and Craigslist, noting that 3taps data makes up about one third of data on the site. “But it varies city by city, and would have more of an effect in certain cities than others.”

The new iPhone  app was the most-requested feature from users so far, Pierson said. Lovely isn’t disclosing user numbers yet, but Pierson said he estimates the San Francisco renter market might include 15,000 to 25,000 people, and Lovely has reached about one quarter of those renters so far (in that they’ve checked out a Lovely listing in the city.) Lovely earns revenue from landlords who list their properties on the site that turn into transactions, when renters report that they’ve found their apartment through the site.

Lovely will also experiment with featured listings, but Pierson said he distinguishes the company from competitors like Trulia or Zillow, which rely more on traditional advertising. The company has backing from investors including Keith Rabois, Benjamin Ling, Walter Kortschak and Thomas Byrne.

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In a claim filed Monday in San Francisco federal court, 3Taps accuses Craigslist of operating as an “unchallenged monopolist” to pull in $100 million to $300 million per year. 3Taps asks the court to declare that Craigslist is violating Section 2 of the Sherman Act, a law that forbids companies from abusing dominant market power.

In particular, 3Taps claims that Craigslist is perpetuating a monopoly through four types of acts: sending sham cease and desist letters against potential competitors; making overly broad copyright claims; imposing improper license terms on users; and “ghosting” (making posts with links to competitors invisibile to other users.

The monopoly allegations are the latest turn in a legal dust-up that began this summer when Craigslist filed a copyright complaint against 3Taps and popular apartment hunting site, PadMapper.

• See also:  Craigslist sues apartment search site PadMapper over listings

The debate turns on who owns the classified ads on Craigslist at a time when up-and-coming companies are creating tools that can show the information in new, visually attractive formats. PadMapper, for instance, lets house hunters see listings superimposed on maps of a neighborhood. Meanwhile, some critics complain that Craigslist’s design and interface is stagnant and stuck in the 1990s.

For its part, Craigslist has suggested that these companies are free-riding on infrastructure that it developed.

The new court filing by 3Taps (embedded below) is fairly dramatic for this type of document and appears geared to further a media strategy aimed at swinging public opinion against Craigslist. But the company’s CEO Greg Kidd also appears to be playing for the win in court by hiring the white shoe law firm Skadden Arps. Here are some selected portions from the complaint (highlights are mine) :

Just as Google, Bing, Ask, or any other general search engine facilitate efficient searches, 3taps enables user-authored ads on craigslist (or any similar public advertising sites) to be efficiently searched. 3taps’ technology provides a previously unrealized public benefit, by enhancing the accessibility of the classified ads of potential sellers by potential buyers.  [...]

Court records show that PadMapper received an extension of time to file a defense to Craigslist’s copyright claim against it. For more background on the case, see Craigslist, 3taps & the court battle for the soul of public data by ReadWriteWeb.

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