Why go to the work of breaking into Facebook or Gmail when you an just exploit this proxy and get Facebook accounts and Gmail accounts and bank web sites and a million other sensitive things too?
Because I would bet that the security professionals working for and contracted by Google and Facebook to be an order of magnitude better at their jobs than those hired by Nokia. I would expect Google and Facebook to be better at closing holes and better at detecting and closing security breaches if and when they do happen.
You know you just agreed with the comment you replied to right?
Oops... I was distracted while reading and didn't read carefully enough.
Because this would only get the information for people who happen to be browsing to those services through specific Nokia phones.