I agree with Judge Canby.
Last year, I agreed with Judge Wallace. Back then, in U.S. v. Giberson, the police had a warrant to search a home for evidence of evasion of child support and saw some evidence in plain view that pretty clearly indicated that the defendant was making false identifications from his computer. So they got another warrant to search the computer for supporting evidence and stumbled upon some child pornography as well. That's okay.
But in today's opinion by Judge Canby, the police had a warrant to search a home for drugs, saw absolutely nothing incriminating, clicked on a file on the defendant's computer, and discovered some child pornography. That's not okay. The warrant here, unlike the one in Giberson, didn't authorize a search of the computer. Nor -- again unlike Giberson -- was there any reason at all to believe that any drug information was on the computer. Hence you aren't authorized to search.
The mere fact that drug information could have been on the computer (yeah, that's why you clicked on that jpeg file, I'm sure) isn't enough. If the warrant doesn't allow a search of the computer, and there's no reason to believe there's evidence relevant to the warrant therein, you can't rummage through the computer's files looking for whatever you might be able to find and charge the guy with.
Judge Wallace gets it right in 2008. Judge Canby gets it right in 2009.