What you can do is send them an email or send a private message to take down your watermarked videos. A slim chance they would take down. I don't advice anyone to report them for many critical reasons and the fact that they have been dealing with copyright issues already. Also, Khmer Avenue and Merlkon cannot afford to run in lock-down setting as I can guarantee everyone that we will lose all the hard earned ten thousands daily visitors we have gained over the last several years. However, the forums are designed to have lock down-sections for the more hardcore visitors.
Though I am glad everyone is discussing about this matter.