Anyone who ever worked with object storage knows that PUT creates, GET reads, POST updates, and DELETE deletes. Naturally, right? POST is such a strange verb with oddball encodings that it's perfect to update, while GET and PUT are matching twins like read(2) and write(2). Imagine my surprise, then, when I found that the official definition of RESTful makes POST create objects and PUT update them. There is even a FAQ, which uses sophistry and appeals to the authority of RFCs in order to justify this.
So, in the world of RESTful solipcism, you would upload an object foo into a bucket buk by issuing "POST /buk?obj=foo" , while "PUT /buk/foo" applies to pre-existing resources. Although, they had to admit that RFC-2616 assumes that PUT creates.
All this goes to show, too much dogma is not good for you.
 It's worse, actually. They want you to do "POST /buk", and receive a resource ID, generated by the server, and use that ID to refer to the resource.