More layoffs at Cisco

Last December there were planned layoffs at Cisco which was known to everyone in advance along with the dates and the percentage of people to be laid off. This seemed fair at the time. Now they have laid off people on a random Monday with no prior information or any talks in the company about the same, managers just told that people who are affected have been informed and not to spread rumours, etc (all managers lingo). Most people were in a higher position in Tech and PMs(as per what I have heard), but surprisingly the managers were not involved and no one knows the criteria of layoff(upper execs did the layoffs). The performance issue was not the cause(confirmed by the manager) then what is the criteria? Does anyone here have any idea what these people see when they do the layoffs? Assuming the project is still on, and the person did not have any performance issues? I am curious. FYI - I wasn't affected (luckily).