Lawful Interception Systems - Research

Hi,

I am looking for any independant information on the above subject as part of some research I am doing. Most of the information I have been able to find is vendor specific.

Additionally initiatives relating to this subject such as CALEA seem to have been only adopted in about 6 countries worldwide. Are there any 'standards' in this area beyond CALEA?

What are the short falls of CALEA compliance? What directions are vendors creating LI solutions likely to head ie. Calea or ETSI?

Additionally I have also found some good publications from the ETSI (European telecommunications standards Institute) http//portal.etsi.org/li/Summary.asp - for anyone who is interested.

Thanks & Regards,