I think there have to be better forms of "mental breaks" though. It's definitely a "work break" but is it a "mental break?" It takes time and mental energy for me to consume content online and even more so if I'm going to comment or add to the content. Ideally, I would make more time for quiet meditation, allowing my mind to actually take a break and turn off the internal dialog/thought engine.
It would be very interesting to see office-type jobs (including jobs like programming) add silent rooms for meditation or even naps (I know Google offered something like that, but no idea about the rest of the industry). Giving people the freedom to take a break whenever they need it and to recharge in that way seems like something that could be very beneficial to both employees and the company. The only problem is that it's somewhat incompatible to a culture where everyone is being micro-managed, so I could see that being a big obstacle.