The API isn't meant for USB flash drives, but other peripherals like keyboards or various Internet of Things crap gadgets. The process isn't meant for some sort of advanced file transfer, either; it's to safely connect hardware to the Web without the need for a dedicated platform.
http://thenextweb.com/dd/2016/04/11/webusb-api/
>>safely connect hardware
Hailing Bill. Is it even conceivable that USB + connect = safely?
Oh forget it. Nobody will ever figure out how to hack this. I think we can all sleep at night.
QuoteAPI hardware manufacturers will have the ability to build cross-platform JavaScript SDKs for their devices..... The engineers also touch on security. A USB device and a computer trust one another by default, so there has to be a safeguard for your data. To help, the engineers plan to invent a type of Cross-Origin Resource Sharing (CORS) which prevents Webpages from requesting data from anything other than the page you're visiting.
That means a Webpage couldn't ever use the USB device to access your computer, or any files that it or the USB device itself may hold.
Quote from: ergophobe on April 12, 2016, 02:58:32 PM
>>safely connect hardware
Hailing Bill. Is it even conceivable that USB + connect = safely?
BadUSB taught us that most USB devices can't be trusted. There's also almost no way to protect against them.