The other day, I was visiting an Overwatch-related Facebook page and I clicked on a link and it took me to a random shopping website.
and this website sold unauthorized Overwatch merchandise, Ranging from posters to t-shirts to hats, among other things and they were using stolen artwork. (Not just official Blizzard artwork, But fan art as well.)
The website itself seemed rather shady. (Usually on "trusted" shopping websites you would see a badge that says: "Trusted Store by Google" or "Verified by Norton".) But the only form of security that I found on that website was a badge that read: "Protected by McAfee". (Which is a brand of anti-virus software that I do not trust.) and it had a notification box that read: "Person from (insert place here) just bought (insert product name here)"
I recommend that you stay away from any shady shopping websites because chances are they might be selling knockoff merchandise or they might not be secure.
If you want to buy officially licensed Overwatch merchandise. I highly recommend that you buy them from either the Official Blizzard Gear store, Jinx or ThinkGeek. (Amazon to a point, But you have to be extremely careful)