http://www.coindesk.com/masked-card-lets-online-shoppers-pay-anywhere-bitcoin/Online privacy company Abine has announced the launch of Bitcoin Anywhere, enabling Coinbase wallet holders to make bitcoin purchases at any e-commerce site
Problem that I see with this is giving them access to your coinbase account. Instead they should provide a QR code and wallet address that you send the correct amount of bitcoins to then it creates the gift card. Otherwise if that company gets hacked they could potentially withdraw your coinbase bitcoins, potentially force your CB account to buy more bitcoins through instabuy and send them and they know exactly who you are via coinbase so not really anonymous. I suppose they want/need to know who you are for AML/KYC purposes in the USA
Not ever site as if te card is visa debit or master card and prepaid debit card most sites in UK have strict access at using them or even applying for items. Some sites will allow it but when using for some shops a lot of the time will not allow them due to being anonymous. A lot of sites do indeed allow them to be used as for to use at any e-commerce site is misleading and false because not all any e-commerce sites accept anonymous pre pay debit cards.