I don't know if you have heard, but some one leaked EXO's dance practice for their comeback song Overdose. Now SM Entertainment is on a hunt to find the person who leaked it, then when they find that person they are going to sue them.

Here is the link for more information:http://www.allkpop.com/article/2014/04/sm-entertainment-files-an-official-complaint-charge-against-the-leaking-of-exos-overdose

It says this:

SM Entertainment previously expressed their intention to take legal action regarding the video leak of EXO's "Overdose" choreography.  Now they have updated on the situation.

SEE ALSO: EXO's mini-album to be delayed for a tentative date

The agency said on April 14, "On this day, we formally filed a complaint charge to the Seoul Central District Prosecutors' Office for the violation of copyright laws, the Prevention of Unfair Competition Act, and laws protecting trade secrets.  

As we have strict legal responsibility regarding this and similar cyber crimes, we will take care of everything in a firm and determined way; hence, there will be additional civil cases and we plan on doing every possible procedure.  We once again inform you that we will be on the lookout to prevent unlawful acts like second and third round posts and circulations."