Instant Messaging usage is growing relative to e-mail usage, and instant messages are discoverable for legal investigations, etc. Here’s a great quote from the article on Mary Mack’s blog over at the Discovery Resources website:
The State relied heavily on the IM messages between the Defendant and the child’s mother to prove their case. Based on the IM evidence and other circumstantial evidence, the jury “reasonably conclude[d] that Defendant had incited [the child’s mom] to use her daughter in a sexual performance . . . and/or to consent to her daughter’s participation in a sexual performance violation.”
There are currently a handful of vendor solutions who provide solutions in this area, Quest Policy Authority for Unified Communications, Symantec, and FaceTime.