Here is some fun stuff on logs and law, again.
EventTracker ~ Newsletter ~ April 2006: "Establishing the authenticity of computer records
Have the records been altered, manipulated, or damaged after they were created?
The mere possibility of tampering does not affect the authenticity of a computer record. Absent specific evidence of tampering, allegations that computer records have been altered go to their weight, not their admissibility.
Establish the reliability of the computer programs that create the records .
In most cases, the reliability of a computer program can be established by showing that users of the program actually do rely on it on a regular basis, such as in the ordinary course of business. Once a minimum standard of trustworthiness has been established, questions as to the accuracy of computer records affect only the weight of the evidence, not its admissibility.
Establish the identity of its author .
Circumstantial evidence generally provides the key to establishing the authorship and authenticity of a computer record. "