I was at Kenna Security when Cisco bought them (I was only there for a month too, so Kenna hired me knowing the purchase was going to happen). They lied through their teeth about the process. They promised every resume would be reviewed for leveling, but then gave out the worst offers I've ever seen. They were literally dropping people by multiple levels, and if anyone complained they told them they couldn't make personal exceptions. They wouldn't even listen to people's managers about it, it was just a bunch of anonymous resume reviews.
At the same time Kenna leadership said they'd pay for Cobra for me if I didn't want to stay. The VP of Eng, David La France, at Kenna promised me that to my face. Then once they sale went through he refused to talk to me and told me to cover it myself. Ultimately they did back down, and were "kind" enough to give me a whole two weeks severance. However it made me realize that Cisco views it's acquisitions in the worst way possible, and if I ever work at a company that Cisco purchases I will immediately start looking for a new job.
It's worth noting that I've kept in touch with a lot of the Kenna people who stayed (at least initially), and according to my old manager more than half of the people who stayed on are gone now.