I want to know the answer to the following question:
What is now necessary to tap someone's telephone?
All the background I'm provided with is that "After the 1967 case Katz v. United States overturned the 1927 case that had allowed bugging, Congress passed the Omnibus Crime Control Act, allowing public authorities to tap telephones during investigations as long as they obtain a warrant beforehand.". Is that enough to answer the question?
Answer: yes