In the US a judge needs to provide much less to the public, "probable cause".

My tinfoil/ CSI tv experience/ common sense tells me you can show a fellow human being something naughty, like illegal sting results, in private if you exert good judgement before, during and after the meeting.

Edit: Where I live, search warrants aren't required by the police. Which is a good thing (for regular people) provided the inaccessibility and corruption of the judicial power.

Yeah I also heard some rumours of a lot of 'anonymous tips' coming from such sources. It can't be proven of course, which is why it's pretty smart of them to do it that way, if they do so.