Can email be forged, introducing false evidence?
Yes, easily (you can do this yourself). You can simply reconfigure your own email system to use somebody else’s email address. This won’t allow you to read their email, but will certainly allow you to impersonate them when sending email out. Another common problem is through the use of “Trojan Horses”. This would allow a hacker to not only forge an email, but to make it come from that person’s IP address as well. Currently, this fools the FBI as well as courts. For example, Fred Modolvski was convicted of posting a fraudulent press release from his machine – he claims that a hacker broke into his machine and sent the message. Currently, no defendant has yet successfully used this “hacker defense”; it would be quite easy for hackers to frame somebody.
