Coinbase seems to feel it's a "feature". 
This "feature" is going to cause some serious concerns quickly if it isn't removed. Just came across this on Twitter today (partial list of Coinbase users and email addresses) http://pastebin.com/RzWipJFb
My email address is public and I didn't get any of these requests or emails..
I'm not sure this is really that big of a deal; it might be spearheaded by a competitor to Coinbase.