It took me all of two seconds to google the typical cultural ways things are done in Muslim societies. There's no way we can take the chance given 9/11 that terrorists won't be trying the same thing on those running port operations.
Produce just one example of terrorists trying to "buy or bully their way into port operations" anywhere in the world, and we'll agree that it's a problem.
Knowing what I do of the East Coast ports, the only bullying we should expect is from the Longshoremen's Union, and that's not likely to go away with a change in ownership.