I'm having a little trouble knowing how to treat all the recent talk about terrorism.

Last week, Homeland Security Secretary Michael Chertoff said he had a "gut feeling" a terror group might strike the U.S. this summer.

Today, U.S. spy agencies have released a report saying al-Qaida is getting stronger.  It says terror groups have stepped up their training in Pakistan.  They may be plotting to sneak operatives into this country to carry out an attack.  The report also warns that "al-Qaida in Iraq" could pose a direct threat to U.S. soil.

We've had lots of warnings like this over the past five years. They are frightening. In each case, the information comes from anonymous tipsters or 'security experts' or 'declassified intelligence.'  Basically, it comes from somebody in the government who is saying "trust us, we know what we're talking about."

And in newsrooms across the country, the information is transmitted on the Associated Press wire service, and we pass it along to you.

But how do we really know if the material is valid?  How do we know if the government is releasing it at a particular time for some kind of political gain?  How can we check independently to see if the information is accurate?

We can't, and that's what is very frustrating.