> After a house is burned down, they are likely to ask everyone around if they saw or heard anything. Heck, they are likely to ask the library in town if anyone

> After a house is burned down, they are likely to ask everyone around if they saw or heard anything. Heck, they are likely to ask the library in town if anyone had checked out a book that outlined how to make a firebomb or similar. Ask local stores if they saw anyone buy fuel that could be used as an accelerant. Expectations are a no in all cases for questions like this, but they still ask. In this case, they asked, "any chance anyone has been looking at this particular address?" When police ask for information in person, the people being asked know about it. When police instead go to Google with a dragnet warrant, the people included in the search never hear about it. But there's a much more fundamental problem, a problem of constitutional rights. A warrant is based on probable cause to believe that someone commmitted a crime. The Fourth Amendment expects a flow like this: Police get a report about a crime. Police investigate the crime scene. Police go in person asking about suspects. With this preliminary evidence, the police have probable cause to pick suspects and get warrants to search the suspects. A keyword search warrant is a general warrant. Police get a keyword search warrant. They search people who aren't suspects. Even if Google does the searching and decides which people to recommend to the police, Google does the searches because the government forces Google to search in the first place. The police use the information to get probable cause to pick suspects. This is backward: the searching comes before the probable cause. The Fourth Amendment breaks in this model.