This isn't uncommon, and as I understand it follows directly from the typical HR policy of only confirming the essentials, such as title, dates of employment and reason for leaving. Companies care more about possible litigation than they do about helping you with your next job.

However, in my experience it's haphazardly enforced. If you're on good terms with a colleague or manager, it's my understanding (IANAL) that they can still provide an informal or personal reference. In practice, for most prospective employers this is just as good as a formal reference (since most companies these days have the aforementioned policy anyways).