As in most other forms of trespass, remedy can only be obtained once it is proven that there was direct interference regardless of damage being done, and the infringing party has failed to disprove either negligence or intent.
These electronic messaging cases, and their progeny, which have cropped up over the last decade, will typically turn on the situations described in (b) or (d), and, as detailed below, the question of harm caused is a big issue.
Some actions constitute trespass and conversion; in these cases, a plaintiff must choose which claim to make based on what amount of damages they seek to recover.
The courts that imported this common law doctrine into the digital world reasoned that electrical signals traveling across networks and through proprietary servers may constitute the contact necessary to support a trespass claim.
Applying this common law action to computer networks, plaintiffs must first prove that they received some type of electronic communication (typically bulk e-mail or spam) that the defendant intentionally sent to interfere with the plaintiff's interest in his or her property and second that this communication caused a quantifiable harm to their tangible property, such as impaired functioning of the computer, network or server.
[4] CompuServe customers repeatedly received unwanted advertisements from Cyber Promotions, a company that specialized in sending marketing email in bulk.
A trio of 1998 cases in the Eastern District of Virginia involving America Online more firmly established the use of the trespass to chattels tort as a spam-fighting tool.
As the spam problem grew worse, AOL had to purchase millions of dollars worth of additional equipment to increase the capacity of its servers to handle the volume of email.
The court held that this activity constituted a trespass to chattels and awarded injunctive relief, reasonable attorneys' fees and costs, as well as damages.
[3] Although Bidder's Edge's robots only consumed a small percentage of eBay's computer resources, the court noted that the plaintiff need not demonstrate current substantial interference as conduct which constituted a use of another's property is enough to sustain a trespass to chattels claim.
The Supreme Court of California reversed the trend exemplified by Oyster in the seminal case Intel Corp. v. Hamidi (2003), reaffirming the need for a demonstration either of actual interference with the physical functionality of the computer system or of the likelihood that this would happen in the future.
The Supreme Court of California disagreed, holding that the tort does not extend to claims in which the electronic communication involved "neither damages the recipient computer system nor impairs its function.
Although the vast majority of states have yet to determine the applicability of the trespass to chattels theory, the courts that have addressed the issue have applied Intel and required that the plaintiff demonstrate damage to the computer system.
A supreme court in New York in School of Visual Arts v. Kuprewicz denied the defendant's motion to dismiss for failure to state a claim on the trespass to chattels claim because the plaintiff had alleged actual damage to the functionality of the computer system, which Intel requires; the defendant had sent enough e-mails that it reduced the computer system's functionality and drained the hard drive's memory.
[12] The Fourth Circuit in Omega World Travel, Inc. v. Mummagraphics, Inc. also followed Intel, although this resulted in granting a motion for summary judgment for the defendant because the plaintiff did not allege any actual damage on its computer system.
[22] For example, the screen-scraping cases indicate that courts might interpret trespass to chattels in such a way that allows major corporations to prevent price comparison sites from employing harmless bots to aggregate information that users want in a readily accessible format since it might encourage consumers to look elsewhere.