He knows nothing and just made a useless post. First of Anonymous is not a group. Secondly their skills are very low, they usually just DDOS. DDOS can be initiated by anyone who has used their computer for a while.
Since it has been brought up here's an image:



OpenVMS is considered a highly secure and reliable operating system relied upon by large enterprises around the globe such as Stock Exchanges, Governments and Infrastructure for critical operations.
It is supposedly the most secure system in the world.


Now, why did someone even mention this?

You've got to be kidding. Check the graph.