He didn't destroy evidence ... it is still on the neighbors' computer. But he prevented his family from being accidently exposed to something horrible.
When I wrote that, I was still under the impression that the files were on the BIL's computer.
However, severing the network connection both alerts the pervert that something is wrong [so that he can take action to destroy the files], and covers up the evidence of the crime in the first place.
Now ChocChipCookie's husband has "accidently exposed" his family [and himself] "to something horrible" indeed: Prosecution on charges of conspiracy to distribute and consume child pornography, and conspiracy to withhold evidence from law enforcement officers.
I keep hoping that ChocChipCookie will get on here and announce that they've contacted the FBI, but I'm not hearing anything.
And I can't believe that their first reaction was not to go to the FBI immediately.
One other technical point about the "destruction" of evidence: The "evidence" is what they can see across the network connection.
If law enforcement can no longer "see" the files, then they have no basis on which to get a warrant to try to find out whose computer the files live on.
Which, of course, assums that someone in ChocChipCookie's family has the gonads to contact the FBI about getting a warrant, which, to date, we haven't seen any evidence of - but, anyway, as things stand right now, the judge has no reason to grant the warrant.