Watch out this video from Redhat about the most common 6 misconceptions about Linux containers.
A typical common question is: are linux containers secure? The response is usually no. Unless you take important countermeasures.
I do believe that the situation won’t change until username space will be officially released. I hope Redhat will do it sooon.
Many people talk about containers without having a clue about the topic. Knowing how to start a container following the result of a google search does not mean master the topic.
Maurizio Benedetti's Blog 