CALEA

CALEA, which stands for Communications Assistance for Law Enforcement Act, is a U.S. law passed in 1994. Its purpose is to "make clear a telecommunications carrier's duty to cooperate in the interception of communications for Law Enforcement purposes and other purposes."

CALEA is controversial in that it seeks to legitimize wiretapping and override user privacy for the purpose of criminal investigations and related police activity. It was originally enacted for telephone conversations, both land line and cellular. The act obliges telephone companies to enable government agencies to tap any phone conversation that is routed over their networks. Companies also have to make call records available on request to government agencies. The law even takes this a step further by stating that the individuals who are being tapped should have no way of detecting this.

In 2005 CALEA was expanded to include Voice Over IP (VOIP) traffic, and so the law now applies to Internet Service Providers (ISP) and VOIP service providers. This means that conversations held using chat clients, such as Yahoo Messenger and MSN Messenger, and VOIP clients, such as Skype, can and may be monitored.

Most IM and VOIP clients do not provide encryption by default. In the wake of this ruling, and to allay user fears, more and more IM and VOIP clients have begun offering end-to-end encryption in their software. While encryption schemes are not unbreakable, it takes a lot more effort to uncover the actual conversation taking place.

As of today, CALEA is limited to voice conversation and does not extend to chatting or cracking email. However, while chat conversations carried out using IM software are not covered under CALEA, voice conversations carried out using the same IM software are covered by CALEA. This is why IM vendors provide encryption as mentioned above.