I have to say that I'm rather disappointed that nobody has mentioned once in this thread that the unconfirmed number of 150 people that have gone missing could be the work of other crocodiles in the area. Find a spot on the Nile that supports one crocodile and tell me that you would still go swimming if you saw it tied up to a tree.
The fact of the matter is that crocodiles, Niles in particular are gregarious animals and while large males are quite intolerant of one another, dominant males share their home ranges with conspecifics and cannot keep out everyone because they cannot be everywhere at once.
The idea that one crocodile could be the cause for that many deaths in a given area is absurd. It would be hunted down and destroyed. People also make crocodile exclusion fences around washing areas and know the dangers of going outside of them. We're not talking about a bunch of stupid Westerners on holiday, these are people that have grown up with crocodiles and know the dangers of going down to the water.
One last thing, to suggest that merely because these people live in a third world country means that they don't have the means to protect themselves from or hunt down and kill a large crocodile is truly offensive. Aboriginal Australians were hunting crocodiles 60,000 years ago. It is not that hard to kill something that breaths and bleeds.