If you live in the Northeast, and I suspect most of you do, you have probably heard of the very publicized sightings of white sharks near Chatham, MA and Westport, RI. People are, to put it mildly, freaking out about it.
This is completely normal. This part of the Atlantic has always been within their distribution and there are a couple of reasons we're seeing so many white sharks this summer. The first is that populations of Grey Seals are rebounding. This is a good thing. But more seals means more sharks. The second reason is simply that we're looking for the sharks more than ever. You won't spot an animal you're not looking for.
Should we be afraid of sharks? I don't think so. We should certainly respect them. I could ask the same question about dogs which bite a vastly larger number of people every year. Yet to my knowledge there has never been a public outcry to go around killing all dogs. Heck, people bite more people every year. All that said, of course, we should not go swimming in water near seals. You shouldn't hold a large metal pole above your head during an electrical storm. If we use common sense and respect the animals for what they are we will not be put into dangerous situations with them.
Check out the state of Massachusetts's shark project here: http://www.mass.gov/dfwele/dmf/spotlight/white_shark_2009.htm
There are some gorgeous photos of these amazing animals.