Huge increase of traffic on HN?

I have just noticed that compete.com shows an overwhelming augmentation of unique visitors on Hacker News in the last months.

https://siteanalytics.compete.com/news.ycombinator.com

I have not found much in HN submission history and I am not sure how to read this data:

* is compete.com data reliable?

* could this be artificial? (e.g. DDoS)

* is this related to a particular event?

* does 1M unique visitors makes sense?

This also may be relevant: http://www.google.com/trends/explore#q=hacker%20news