And then this happened. 
Epilepsy fears over 2012 footage
A segment of animated
footage promoting the 2012 Olympics has been removed from the
organisers' website after fears it could trigger epileptic
seizures.
Prof Graham Harding, who developed the test used to measure
photo-sensitivity levels in TV material, said it should not be
broadcast again. Charity Epilepsy Action said it had received calls
from people who had suffered fits after seeing it.
Organiser London 2012 said it will re-edit the film.
...
Emphasising that it was not the logo itself which was the focus of
worries, 
she said: "This concerns a short piece
of animation which we used as part of the logo launch event and not
the actual logo."
She said the section of
footage concerned showed a "diver diving into a pool which had a
multi-colour ripple effect".
The spokeswoman said: "We are taking it very seriously and are
looking into it as a matter of urgency."