It appears that many sellers advertise colourful art glass as Murano, when in actual fact the item is not. And, Ebay should not allow sellers to class an item as such if it is not genuine.
Murano glass is specifically made in Murano, Italy. Not in Russia, China or elsewhere. And, it always helps any buyer to do some research via the internet, before looking at pieces and placing a bid on ebay. It is always hard to get the right answers most times via research on the internet, especially if your searching for a specific piece. But, one thing you will learn is history on Murano glass, dates it began, artists, and even how Murano glass is made today.
If you are a buyer, and a amateur like myself when it comes to Murano glass, but love the artwork, and would like some pieces of this beautiful art glass. It might be worth your while to search for pieces on ebay that have the Murano sticker still on the artwork. As there are many copies of Roosters, Clowns etc that are not genuine Murano pieces. Therefore, a piece with the original sticker, would be your safest option when looking at pieces of colourful art glass.