Is Interfolio Protecting the Confidentiality of Letters of Recommendation?

A philosopher elsewhere writes:

There is something going on that might be worth discussing. I think it might be fairly common--at least, I suspect it is fairly easy to do--to see one's letters of recommendation if you use interfolio. All you have to do is have them sent to a friend or set up a dummy recipient address. Candidates have an interest in seeing their letters, and I would be amazed, unless there are controls I don't know about, if people weren't doing this. *As far as I can tell*, there are no controls on Interfolio of the usual sort that a department would normally impose if it were the entity sending out the letters, ie only sending it out to advertised job addresses, etc. 

Is this right?  Have readers heard of this happening?  Signed comments preferred, but all comments must include a valid e-mail address at least.