One of the biggest complaints I see in the forums is from publishers complaining their Google AdSense accounts were suspended or banned but claim they have no idea why.
Well, Google has been listening over the past ten years and finally is introducing more detailed policy violation notifications via email and within the AdSense console.
Going forward, if our system detects a policy violation, you’ll receive both an email and an account notification with a link to view more details. Under the Policy violations section on the home tab, you can quickly access important information including details on each violation, the issue ID and an example of the violation on your site. The page will also include details on the action you need to take to resolve the violation.
Here is a screen shot of the alert in the AdSense console:
Here is a screen shot of the details you may see in such a notification (click to enlarge):
Honestly, I am a bit skeptical if this will really do it for those who were suspended or banned, but time will tell.
Forum discussion at Google+.