It's a personal issue of security...since he went to the trouble to blur out the HD name in the corner, I thought I'd point out that it was visible in the sidebar as well, in case he had overlooked it.
I had a similar problem before. Seems your suitecase or whatever you use for managing fonts is activating a numeric font set. Try checking all active fonts and see if one of the font families is different.
Or just deactivate all added fonts and try running the OS X fonts only.