What's more worrisome: OSes that spy on you, hardware that enforces spyware OSes, or the fact that you can't use pretty much any of the modern internet without executing arbitrary, untrusted code on a JIT built and distributed in binary form by a giant multinational advertising company that has a PRISM api?
perhaps it's time for a web browser that uses a non-JIT js interpreter, even if it's 20x slower.