[bogomipz]

Not only is not common but it's definitely not "extremely common." In the current wave of layoffs signaling the end of the "cheap money era" it does seem more common however. At least among the types of companies that are likely to make it onto the HN front page. I've worked for plenty of startups where we got nothing more than being paid up through the day we were laid off. And most of those withheld our last check until we returned all company property.