My understanding is that if you leave the connection unencrypted you are in a better position in court, because the prosecutors can’t prove you were the one doing the illegal downloading (etc.)
The recent RIAA litigation success may show otherwise.
It was three weeks before he was arraigned (they kept him busy with paperwork and stuff, he was at home, they did lots of negotiating and plea offers) and after arraignment FBI called his work and told them he’d been arrested, so he lost his job. They issued a court order for him to stay away from children or where children congregate (like his daughter’s school and church school and soccer) and sent a copy to his daughter’s school.
Things went along these lines for a while. Interviews, lawyers, documents to sign, permissions to give, negotiations with his lawyer. Very costly considering he’s out of work now.
Around month six, they announced that they’d gone over everything and had discovered actionable items, he was going to be charged. It took another year, maybe 18 months, before things got settled. He’s doing time in lovely LA harbor now as you read this, for possession of a bunch of pictures, over 200 which is a breakpoint for the sentencing guidelines. He pled guilty, by the way.
No, this had nothing to do with wireless, but it’s the six months from warrant to charge and the money he spent that’s disturbing. If they had found nothing, he’d still be out of his old job and missing lots of his savings.
Even if the whole process took four months and he got acquitted, it’s easily avoidable (don’t look at porn and keep your wireless locked up).
So yes, it helps in court, but believe me based on this guy’s experience there is much unpleasantness before you even get to court.
I keep my router locked up tight!