A briefcase used to just be a briefcase.

Find a briefcase without its owner in the post-9/11 world, though, and it's a security issue.

"Anytime you have a big, huge event like 9/11, it's inevitably going to have an impact on how people think about their daily lives, and in fact that's exactly what the goal was of 9/11," said David Smilde, associate professor of sociology at the University of Georgia.

David Kimbrell, Hall County emergency management director and fire chief, said that mentality has changed the way local authorities work.

"All the training has kind of focused to, in a bombing, look for a secondary bomb, or a bomb threat, to actually pay attention to that, as well as suspicious packages," Kimbrell said.

Even someone taking photos of a building or other structure can become a concern, Gainesville Police Chief Brian Kelly said.

"A lot of times those things pan out to ‘they're just tourists and they've never seen a dam, here at Lake Lanier, like that before,'" Kelly said. "If it pans out to be nothing that's great, but you never can tell where that piece of information may end up being."

In October 2001, the Hall County Fire Department's hazardous materials team responded to a call at the Gillsville post office after a clerk dumped a sack of mail and noticed white powder on the mail and in the sack.

Five deaths due to anthrax spores that were mailed to various places throughout the country in the months after 9/11 had raised concern.

Kimbrell said the substance turned out to be dishwashing detergent that leaked out into the mail sack.

"Everything turned out to be nothing," he said. "It's just people were hypersensitive about everything going on."

Kimbrell said the fire department treated the situation seriously because of the string of similar incidents.

"We treated it seriously because we didn't know at the time and we were hypersensitive, so we treated it just like it was an actual incident where we went in completely suited up (in hazardous material suits) and cleaned the area," Kimbrell said.

Smilde said in many cases the fear is disproportionate to the actual danger.

"I think it definitely changed people's thought processes in that it made it seem like it was problem that was here in the United States," he said. "I think that made people think ‘that could be me.'"

It's the decisions people make based on fear that Smilde says is the biggest threat, though.

"The way terrorists work is they try to make people fearful in that they make bad decisions, and that's what people have to keep in mind. And they should instead focus on more concrete dangers," Smilde said.

That doesn't mean people shouldn't be cautious, but it shouldn't affect their everyday decisions, he said.

"We do live in a world that has conflict ... and so people need to be aware of that," Smilde said. "... But it needs to be kept in perspective and make sure it doesn't affect our decision processes."