"Police merely state that they received reliable word from a reliable source. No judge will make them elaborate or name names. After all, the informants identity must remain silent to protect their sources. This is how a substantial number of narcotics raids are initiated"
That is not how it works. When a search warrant affidavit is based soley on witness/confidential informant information the witness/CI will have to testify in front of the judge during the process of getting the warrant and his identity will be known to the judge. The affidavit has to particulary describe the place to be searched and the specific item(s) sought. It not only has to deal in specifics, but must set them out so that a neutral and detached judge can independantly determine if the information demonstrates probable casue to justify the warrant. Merely stating that "I received reliable word from a reliable source" will never get a warrant signed.(or shouldn't) Any judge worth anything would NEVER sign a search warrant based on that and no cop with half a brain would even consider applying for a warrant based on such information. Sure it could happen, but a 1st year law student could easily defend against that and have the search tossed in about 2.5 seconds.
CI's are never completely confidential. They must be registered and proven reliable, especially when basing a search warrant on their information. If a case goes to trial the CI will have to testify and his identity will become known to all. That is why you see so many narcotics cases plead down. No one wants to burn a good CI unless it is for something really big.