U.S. Supreme Court says you don't need a warrant, Oregon Supreme Court says police must show good cause to search for weapons

http://rt.com/usa/police-warrantless-search-permission-744/

Excerpt from link above:

The US Supreme Court has ruled that police may search a home without obtaining a warrant despite the objection of one occupant if that occupant has been removed from the premises.

With its 6 to 3 decision in Fernandez v. California on Tuesday, the Court sided with law enforcement’s ability to conduct warrantless searches after restricting police powers with its 2006 decision on a similar case.

http://thehill.com/policy/national-security/245696-supreme-court-strikes-down-law-allowing-warrantless-searches-of

Excerpt from link above:

The Supreme Court on Monday ruled that a municipal law forcing hotels to give police information about their guests without a warrant is unconstitutional, in a major win for privacy advocates.

In a 5-4 decision, justices declared that the 1899 Los Angeles law violated the Constitution by depriving hotel owners of a chance to challenge the ruling. 

http://www.oregonlive.com/portland/index.ssf/2015/07/cops_must_have_good_reason_to.html

The Oregon Supreme Court ruled police must have a good reason to search for weapons