title: GCM sender id / project number
body: <p>to send a GCM, we have a SENDER ID from Google API console, is that important to keep that SENDER ID protected? I mean, would someone be able to do bad things if they know that ID? I did a mistake and I think that ID was in one of my projects... am I able to somehow change it? I couldn't find anyway to change it by looking at the Google API console!. should I be worried about that? or is it ok?</p>
  
  <p>the server and browser API keys can be changed but not the SENDER ID, PROJECT NUMBER...</p>