Cisco Support for Lawful Intercept in IP Networks

What are service providers doing concerning lawful intercept support in their networks? Fred Baker, et al published an internet draft this month (April 2003) containing a lawful intercept architecture. http://www.rfc-editor.org/internet-drafts/draft-baker-slem-architecture-00.t... Has anyone gotten a real set of requirements from the FBI for lawful intercept in IP Networks? Would Cisco's proposed architecture work, or just result in buying more cisco equipment?