Ironically, one of the violent tacklers (who heroically defended Whole Foods) turns out to have tackled a 'girl': (http://www.reddit.com/r/occupywallstreet/comments/lzdar/iama_oakland_general_strike_protester_that_fought/)
(This man was credited as the tackler, by the journalist who uploaded the Youtube video.)
The tackler goes on to mention that he'd like to record defacers and "give a copy to the police". And further asks, "Any martial arts that works well against groups of people?"
Now personally, I can imagine that smashy-smashy tends to be counterproductive. It can easily be rather racist, classist and ableist, when the smashers are unaccountable to those unconsenting people least able to bear the expected retaliation. (And as I hear, "smashing things up" is actually a relatively recent interpretation of anarchism. [1])
But it does highlight some odd problems on the left. Like the hyper-violence of those like the tackler I quoted, and the ageist slurs on display here. (As much as leftists mention how important "the youth" are, and how they tend to be more left than the population... there are clear signals that younger people may find problems with leadership-promotion on the left. And that important youth issues may be virtually dismissed.)
That said, "STRIKE" is probably the best message to spraypaint, as done in the video. Maybe an innovation is to bring neat stencils saying "GENERAL STRIKE", and spraypaint that everywhere. Because it'll look attractive, be a wholesome family message, and there may not be enough resources to remove them all quickly.
All the best,
Tj
[1] http://www.anarchistblackcat.org/index.php/topic,6772.msg70364.html#msg70364