I feel a sign of a mature company comes when they have to react to something going wrong. A couple days ago I received an email from my hosting company, Media Temple, about someone illegally hacking some old client records that had not been encrypted and made off with account details. Of course this is not a good thing, but they have corrected the problem and implemented additional security in order to track down accounts that have been compromised.
Oh happy joy, I receive an email walking home yesterday to say that mine was one of the hacked ones. The email notification was very good and even provided links to articles about finding and correcting the hack, as it had occurred in only specific files and changing the various passwords attached to my account. This was very well done and only took me a total of about ten minutes to do.
I am not saying it is a good thing when a hosting provider is allows something like this to happen, but it is a very good sign that they dealt with it quickly, efficiently and most importantly transparently.