I think you're right. There are definitely plants in occupy oakland. It's been done before, and they're doing it now. Not only do the plants seem to get everyone riled up and try to make the whole movement look bad, but somehow the police already know exactly what is going on (there were freaking snipers inside the Kaiser building that was going to be occupied on Saturday, before anyone got there)
That's an acetylene explosion for show, following the design from the book "backyard ballistics". There is no projectile, and if there was, it could easily be lethal to the operator. And again, they have heavy assault weapons, and non-conventional and chemical weapons like the LRAD. Shoot that thing, even without a projectile, and you will have a lot of blood on your hands when they mow the whole crowd down. Blac bloc tactics are what they are for good reason. If you resist and use shields and smoke bombs, they don't like it, if you have improvised artillery they use the real stuff.
Over in the Occupy NYC thread I posted about Tim from Timcast getting attacked by "Blac Bloc" http://www.hipforums.com/newforums/showthread.php?t=438089&f=633&page=15 He is the one I also posted an Occupy thread about who does the Occucopter http://www.hipforums.com/newforums/showthread.php?t=441284&highlight=technology&f=633
Anonymous Hacks Oakland Officials In Retaliation For OWS Crackdowns http://rt.com/usa/news/anonymous-oakland-officials-police-719/
The Occupy Oakland Website Says The Anti-Police Brutality Marches Will Continue "Weekly On Saturday -- Forever." http://www.mercurynews.com/breaking-news/ci_19949260
Occupy Group Confronts Pro-White Rally at State Capitol http://www.thehindu.com/news/international/article2941585.ece
May Day strike to shut down Tuesday morning ferry service http://www.mercurynews.com/breaking-news/ci_20517240/may-day-strike-shut-down-tuesday-morning-ferry