The concept of a "security theater" is one that is often used by security expert Bruce Schneier. It's used to describe "security countermeasures intended to provide the feeling of improved security while doing little or nothing to actually improve security." There's a list of examples, if you are curious... And I think that we might be able to add one to the list: London has bought some expensive fuel-cell powered electric buses and put them on popular tourist lines to showcase the technology. It's even likely that they bought the buses for the olympics in the first place. But these buses have now been ordered to stay parked during the olympics "in the interests of security", and the hydrogen refuelling station used by the buses has been ordered not to store hydrogen on location for the duration of the games.
This seems like the very definition of a security theater, based more on perception than actual reality. The perception is that hydrogen is this very dangerous thing that explodes easily, etc. But the reality is that reinforced hydrogen tanks are rigorously tested and pretty much assuredly safer than your average gasoline or diesel fuel tank. And even if a H2 tank is breached, it is less likely to combust than the equivalent gas/diesel -- it is more likely to very quickly escape out in the atmosphere and rise rapidly (because H2 is so buoyant), and then combined with oxygen to create water.
Our colleagues at How Stuff Work have a piece about hydrogen fuel safety that gives more details on this, if you're curious.
This seems to be a case of people discounting the risks that they are familiar with (diesel) and fearing things that they aren't familiar with (hydrogen), even if it is likely to be safer.