To hijack something is to forcefuly take over something in order to
alter its direction for your own purpose.
A meme hijack is just that: When a memetic engineer splices
a meme in with another more successful (more horizontal) meme in
hopes that his meme will carry on with the other meme.
Recent examples include Hewlett-Packard's use of the plus
sign (+) in their advertising. Essentially, they hijacked the
plus sign by splicing in their own logo (hp) into the meme. The
Hewlett-Packard hopes that whenever you see the plus sign, you
will think of the small hp also, and therefore think of
everything Hewlett-Packard represents to you. Hewlett- Packard is
some no-good dirty meme hijackers.
Level 3 Software hijacked the parenthese. They are some low
down dirty meme hijackers, as well.
Since you simply cannot unthink the neural
connection between the host meme and the viral meme, you are
stuck with a probability greater than zero of thinking about the
hijacker meme when you see the host meme.
Another example would be Burger King hijacking the song
"Stop The World" with their dirty little fat burger
memeplex. I'm all for locked cockpits on all memes.
Damn little hijacker