It so happens that Prosecutor Kirchner got that search warrant based on his probe into some other corrupt drug dealer, who was apparently selling pills through Limbaugh's housoekeeper.
In other words, it's as if a cop went out and got a search warrant to check YOUR house based on something your neighbor did, but then while the cop is inside YOUR house, he decides to snoot around to see if he can find anything else that looks to be illegal.
And we haven't even taken into account that this hypothetical cop (being a Democrat) just happens to hold a grudge against you (being a Republican) and therefor would further his career if he was to make a bust.