When government agents are lawfully executing a warrant they can take anything they want for any reason?

No, the police don't have the right to take anything for any reason even though they have a warrant. First, the warrant must be a search warrant for the police to be able to enter the premises to search specific items. The search warrant must be approved by the judge. When the judge reviews the warrant, it must contain the specific location and the specific type or category of items that are to be searched. So, the police must only take the items that are specified in the search warrant. Taking anything for any reason other than what is specified in the warrant is a violation of the owner's rights.