EFF Analysis of trespass to Chattels Legal Theory

As Applied to the Internet in Intel v. Hamidi

The Issue:

Litigants eager to block certain people from accessing their servers have increasingly turned to an antique legal doctrine called "trespass to chattels". Several courts have recently recognized this as a valid legal theory.

"Trespass to chattels" basically prohibits others from substantially interfering with your personal property ("chattel"). Generally speaking, there must be an intentional physical contact with the chattel, and the contact must result in some substantial interference or damage.

Several cases have imported this antiquated common law doctrine into the digital world, reasoning that "electrical signals" impinging on networked servers can be enough "contact" to support a trespass claim. Some examples:

  • A court concluded that phreakers who were using purloined authorization codes to make long-distance calls were "trespassing" on the telephone company's system. [see Thrifty-Tel v. Bezenek]
  • A former Intel employee sent unsolicited email to current Intel employees, expressing criticism of Intel's policies. He continued this practice after Intel warned him to stop. A court found that these unwelcome email messages constituted a "trespass" on Intel's mail servers. [see Intel v. Hamidi]
  • eBay sued Bidder's Edge for crawling the eBay website for auction listing information. The court concluded that, by continuing to crawl eBay's site after being warned to stop, Bidder's Edge was trespassing on eBay's web servers. [see eBay v. Bidder's Edge]
  • Register.com sued Verio for using the Register.com WHOIS look-up service to find customer leads on recent domain name registrants. The court found that, by continuing to access the database after being told to stop, Verio was "trespassing" on Register.com's WHOIS server. [see Register.com v. Verio]

The Problem:

Some feel that the "trespass to chattels" theory should be embraced because it provides a weapon against "spammers". While that may be true, the trespass theory has many dangerous implications that reach far beyond the spam context. For that reason, EFF believes the expansion of trespass theories to cyberspace is unwise.

For example, trespass theories have been used to stifle legitimate competition. "Price comparators" have been blocked from gathering price data by threats of trespass suits. Both the eBay and Register.com suits are examples of companies attempting to limit competition and access to information.

Trespass theories can also be used to stifle free speech, as they have been in the Intel v. Hamidi case.

Trespass theories might also be used to block search engines and linking, and thereby threaten two of the most important architectural aspects of the Internet. After all, if you continue to offer a link to another site after being warned that the traffic you generate is not welcome, you could fall within the reach of trespass law. Similarly, a search engine could face trespass liability if it did not comply with a request to stop crawling a site (note that this would be *selective* blocking of particular search engines, unlike robots.txt restrictions).

The essential problem is that trespass theories create a new kind of intellectual property with no limits. This could result in a very different Internet, one where every email message, every ping, every http request could be the basis for a trespass claim. ISPs and server owners would simply have to deliver a notice in order to trigger trespass protections.

Of course, an entity can use dynamic URLs, or a password system, IP filtering, or any number of technical measures to restrict access to their site. Unlike trespass theories, however, technical measures generally do not permit server operators to discriminate between users based on the content of their messages, their status as competitors, or other troubling criteria.

There may be a need for legal regulation of certain unwelcome messages (such as spam or ping flooding attacks), but these regimes should be carefully tailored to address particular problems. The doctrine of trespass to chattel, in contrast, could have broad chilling effects on many desireable features of the internet.


For further elaboration on this issue (including case citations), see:

Dan Burk, the Trouble with Trespass:   http://www.isc.umn.edu/research/papers/trespass-ed2.pdf

Law Professors brief in eBay v. Bidder's Edge:   http://jurist.law.pitt.edu/amicus/biddersedge_v_ebay.pdf

EFF brief in Intel v. Hamidi: http://www.eff.org/spam/Intel_v_Hamidi/20000118_eff_amicus.html