Yes, law enforcement officers should be able to use hacking tools to search computers that are connected to the internet. If there is a chance that officers can find a suspect or a criminal, then they should hack computers. However, they should not invade personal property. They should be allowed to search any device that can help them with their case but not expose an innocent person.
I don't see any reason why the police shouldn't be able to do this if they have reasonable suspicion that a person may have or may be planning on committing a crime. For the ordinary person, you should have nothing to hide, and shouldn't have any reason to worry about it. For criminals, if you are doing something illegal, then you deserve to be caught.
No, law enforcement officers should not be allowed to use hacking tools to search computers just because they are connected to the internet. Allowing the police to conduct such searches without probable cause is a violation of the 4th amendment right to be free from unreasonable searches and seizures. This would thus violate the Constitution.
Computers that are connected to the internet is rather a broad stroke, unless, of course, we mean simply computers that are physically wired to the cables of the internet. Law enforcement, with due process and a warrant, should be able to hack in the interest of security and criminal justice, but it should be severely limited to those cases.