At first that I thought this was pure joke, perhaps a parody of some kind. A made up incident; nothing that bizarre could be true.
Then it occurred to me that it might be a reference of some kind. Some sort of strange geek culture thing. So I googled it, and discovered something both deeply disturbing and incredibly amusing.
It actually happened.
On April 20, 1979, the President of the United States was attacked by a giant swimming rabbit.
It ought to be a holiday.