Personally I think there should be a law restricting all these copycat going on recently, well I don't know if there is one but it seems Mark is playing his game tightly if at all there is copyright law and Mark Zukerberg might just win this game of copying Snapchat.
Instagram now has most of Snapchat's filers in their application, according to some Instagram users, it looks as though the new Instagram filters are even more advanced than that of Snapchat. Not only do they add filters but they have also added a "Rewind" feature in the camera mode which will allow users reverse any action. This feature is also available on Snapchat as well.
Seriously I think Snapchat is heading toward its doom and Mark Zerkerberg (Facebook, Messenger and Instagram) is making it come fast.