Check out this link to see the jumping behavior Silver carp exhibit here in the USA.
http://www.protectyourwaters.net/Asiancarp.rm
They don't 'attack' people, they just jump into them. Getting hit upside the head by a 25lb fish is plenty dangerous.
Here's another link about the potential ecological impact the Asian carp may have.
http://www.optimizethroughdesign.com/testpage.htm
(my solution... everybody should go bowfishing)
Here's a pic of my buddy Dave with a bighead carp... lots of tasty filets there.