By Justin Udo

PHILADELPHIA (CBS) — The frustrating pat downs, inconvenient searches, and the worry of carrying banned items, are now post-9/11 norms at airports across the country.

Erik McCarroll with Homeland Security says the Transportation Security Administration wants you to know they have good reason to check your laptops, limit your liquid sizes, and have you take off your shoes.

“The one thing that the terrorists have become accustomed to is being able to take a common item that you see every day, and modifying it in a way that you can’t tell just by looking at it that it’s been modified to do their dirty work,” McCarroll said.

McCarroll says shoes, shaving cream, and drinks are sometimes more than what meets the eye, because they all can be used as bombs.

“It’s such a huge gammit for us. There is not any one thing that occurs all the time. Such a large array of attempts by people is what we see,” he said.

He says, believe it or not, people have tried to bring real and toy grenades on to planes, both of which are banned items.

“We get probably about 40 to 50 a year just here at this airport,” McCarroll said.

Mike England with the TSA says agents get more than 100 hours of training each year, to look for and detect items they say should not be on the plane.

“They go over all of the items to do their job. They get X-ray training, they get pat down training, basically they get trained on every aspect of their job,” he explained.