The news is reporting on people buying up Potassium Iodide also known as KI in droves and that suppliers have run out and are scrambling to make more. One supplier has also donated a large supply to Japan.
I also know several preparedness retailers who have also run out and have a large number of orders being placed that they can't currently fill. The two things that worry me about this is first, the people who may need them may not get them since the supply is short (though governments do have stock piles of them) and the second is the potential for people who should not be taking KI to have adverse side effects.
Some facts you should know about KI:
Other side effects include: acne, loss of appetite, or upset stomach. More severe side effects which require notification of a physician are: fever, weakness, unusual tiredness, swelling in the neck or throat, mouth sores, skin rash, nausea, vomiting, stomach pains, irregular heartbeat, numbness or tingling of the hands or feet, or a metallic taste in the mouth.
Severe allergic reactions from taking KI are possible especially if you have certain food allergies.
People who should avoid KI:
Lastly KI is considered a possible teratogen (meaning birth defects or developmental issues in young people).