I thought that roving wiretaps were one of the more reasonable provisions of the anti-terrorism bill recently signed into law. Tracey Maclin, a Boston University law professor, clearly articulates the dangers of that provision and explains how it violates the Fourth Amendment in his National Law Journal article, On Amending the Fourth. Here’s an excerpt:

One might argue that a wiretap that follows the person rather than a particular phone better protects privacy than a traditional search warrant because when the government obtains a traditional warrant to monitor the telephones of a particular location, all the conversations that occur at that particular location will be subject to surveillance. Under the new law, the government contends that it will focus only on the conversations of the target.

But if the government can assign the wiretap to the person so that it can gain intelligence from a person who uses multiple telephones or changes cellular phones, then the conversations of all people using those devices will be overheard. For example, if the government suspects that a particular target uses different pay phones at Boston’s Logan Airport, then the government would have the power to wire all the public telephones at Logan Airport and the discretion to decide which conversations to monitor.