In the case of the Oakland general strike, there's a pretty obvious logic behind the window smashing. The general strike was fairly openly intended to be coercive, that is, to involve forcing businesses to close to allow employees to take part. Oakland was covered in posters saying things like "all banks and corporations must shut down, or we will shut you down." One way to force a business to close is to break its windows. Whole Foods specifically was targeted because the store threatened to retaliate against employees who took part in the strike.
I'm not saying that smashing windows was, on balance, the best way to try and force businesses to shut down for the day, but the connection between the action and its intended effects seems pretty clear in this case. --
"Why must man's vocation always be to distinguish
himself from animals?" http://blog.voyou.org/ -- Baudrillard