Cyber-trespass and 'Unauthorized Access' as Legal Mechanisms of Access Control: Lessons from the US Experience

The common law doctrine of trespass to chattels has recently been revived and applied by courts in the United States (US) to cover intrusions (in the form of electronic signals) to computer systems connected to the Internet. These cases represent judicial recognition of the need to protect certain unwanted intrusions in cyberspace, though the principles developed therewith are remarkably expansive. As such, they overlap with the concept of 'unauthorized access' under computer misuse legislation in the US and elsewhere. This overlap has yet to be judicially acknowledged. Since the US, the United Kingdom and other common law countries not only share a common law ancestry but also 'unauthorized access' principles as the primary trigger for computer misuse, this paper seeks to examine the consequences of developing a broad cyber-trespass doctrine beyond the US, and its corresponding implications for judicial interpretations of 'unauthorized access' in the common law world.