I run an IT security company and have been in hundreds and hundreds of companies. I have also been in hundreds of commercial datacenters and cloud provider facilities.
As a rule they take security very seriously. The smaller application providers are more challenging in some cases but the big ones are quite good.
It really comes down to basics, it is extremely expensive to run a datacenter properly. Companies cut corners on the necessary infrastructure, tools, and employees necessary to do it properly.
In the software development business since late 80’s and I haven’t seen anything that is 100%. Where there is a will there is a way and the government has the way and the will. Loser hackers have the will in most cases.
Case and point - http://www.freerepublic.com/focus/f-news/3197814/posts