They can be a danger to kids (just about anything can be a danger to kids) and that is good to know for people who may not realize the power in rare earth magnets. But, more importantly, the use of rare earths creates a dependence on China that is critical although new companies are now trying to fill the supply gap. That makes a good stock market emerging market if you trust in such things. Also, the conditions at such mines and the corresponding factories are lethal with likely many generations of Chinese and 3rd world laborers going to die like the early days of the coal mining industry. Better extraction and refining methods are needed as well as alternatives to rare earths which are being pursued. I have written a few articles on the rare earths and these magnets:
are a few.