Techies, online cell phone buyers and YouTube video watchers are currently the only source of unlocked phones in the U.S., but that may soon change after the Senate approved a bill Tuesday to legalize unlocking of cell phones by their carriers.

Elsewhere in the world, the idea of an unlocked or multi-SIM card phones is prevalent, but the U.S. has long been left out of the trend.

PC Mag reported in 2010 that dual-SIM phones were popular in Latin America because of the system of competition set up by carriers.

In South America, the cell phone carriers offer better rates for their own customers, so many individuals buy two SIM cards for competing networks, and use it in one phone, according to PC Mag.

In Europe, the same system exists, according to industry expert Andrew Seybold in a 2010 article.

The bill which passed unanimously in the Senate Tuesday night is now waiting for final approval from the House of Representatives.

Locked cell phones became legal in 2012 when the U.S. Copyright Office determined customers would have to seek approval from their carriers, even if they had finished a contract, in order to unlock the phone and switch to a different carrier, according to Scripps Media.

But in 2013, a petition with more than 100,000 signatures seeking a repeal of the decision was sent to the federal government.

As a result, the Unlocking Consumer Choice and Wireless Competition Act was introduced.

Vermont Sen. Patrick Leahy (D) had introduced the bill and said in a statement that it "puts consumers first and promotes competition in the wireless phone marketplace."

The bill essentially reinstates a 2010 ruling by the Librarian of Congress to allow unlocked phones, but also asks the Librarian of Congress to consider unlocking of other wireless devices such as tablets, according to Leahy's statement.