 An example would be an email from a suspect in another case to a suspect in this case, or contact / phone calls to a witness from a suspect.To compound the issue, there has been a massive increase in the size of the data that the computer forensic expert needs to collect.It is now often the case that the computer hard drive is not able to be imaged, for example if the computer that contains the evidence is too big, or the system cannot be shut down to take an image as it is a mission critical server such as an email server or company file server.