france and germany. the u.s. state department urges americans to use "common sense precautions." but some say the advisory are way too vague and hold little value. tom fuentes and francis townsend say it would have been better to say nothing at all. >> i'm a real believer. if these warnings -- these public warnings and alerts that get put out don't tell people specifics about either locations, timing, or what they can do to protect themselves, then we shouldn't bother. we shouldn't scare them about something that they can't protect themselves from. >> i agree with fran. maybe even a little stronger than fran that issuing a warning like this is on the verge of being completely ridiculous. there are thousands and thousands americans in europe. everybody's going to look different to them. everybody is going to be carrying a backpack and looking strange if they were walking down the street in peoria, illinois, for example. >> they're saying the travel alerts were issued because of growing concerns that terrorists may be planning a commando-style attack in europe like the one that happened in mumbai, india in 2008. that incident lasted three days, 166 people were killed. cnn's senio