Guns don't kill people, people kill people. Using guns.
In this case I agree with the sentiment, it wasn't blogging that got Mark Jens fired, but blabbing.
Unfortunately I wasn't able to read the particular Jens post that caused the ruckus. If it was truly about employee benefits, I don't know what he has to complain about. I've been on Google's campus, and it's very nicely appointed, and they have the creme de la creme of employee benefits: Free Drinks.
When I interviewed at Microsoft (1997) that was supposedly a big deal, that everybody got free drinks. In my early days working for Javasoft (er.. at the time it was the Java Software Division of Sun) we had free drinks. Looking back I'm thinking "big whoop" but at the time it seemed like a big deal. What really counts in terms of benefits at Google is the 20% time to do your own thing. That's a huge investment on Google's part, and truly a big thing. So I can't think of anything he coulda been complaining about of any significance.
The blabbing thing is the key here. In my previous posts on this I've been focusing on the danger of having too strong a restriction on employees talking about their employers. There is another side to it, of course, since there's lots of reasonable room for employees to keep quiet about what their employers are doing. e.g. An employee usually is in agreement with the projects they're working on, they want their projects to succeed in the market, and for competition sake that means keeping details of the project quiet until the big brass are ready to reveal details.
Scoble, an infamous Microsoft employee with a well followed blog, raises an interesting point. "Be smart" is his mantra, which is shorthand for "don't piss the boss off". In Mark Jens' case he claims that Jens didn't follow rule#1, which was to establish a relationship pool within the workplace before blabbing.