I'm sure all of you have heard about Ke$ha's Run Devil Run...
And I'm sure a lot have heard about 소녀시대 aka Girls Generation's version of the song as well..

So I'm pretty sure all of you are asking the same question...
Who is plagiarizing who..??

The fact is...
No one is plagiarizing anything...
Ke$ha's version was just a "guide song"...
What is a "guide" song?
It's a demo song...
It was recorded before the song was launched..
So Ke$sha did not have the rights to the song...
Since SNSD launched the song first, so they have the full rights to the song..

So there you go...
All the questions running in your head is all resolved!!!

Source: Korean Top News