Everything else
Have you ever been to an airport, or even just the DMV? Think of the people who've been in the line with you. Imagine going through their underpants. Imagine having to touch them. Imagine having to argue with them, deal with them day in day out. Imagine having to take a snow globe they bought as a present but didn't check with their bags. Now imagine doing all of that knowing what happened in Brussels could happen at any time/ at that moment - that precise moment, because if they get to you everything else has failed - you are the only thing stopping another tragedy. Sound like a good time? Congratulations, you're a.. word glassdoor wont let me use.
Welcome back to high-school. Some of these people are fresh out of high school or never graduated from high school. They bring it with them. That and the horrible working climate brings everyone susceptible back to a state of petty gossip and tantrums.
You better not be susceptible to peer pressure, because some TSOs don't want to do any work that doesn't result in a real prohibited item, and they'll give you an earful every time you call for a bag to be looked at that has nothing but clutter. The job is not easy, these people need to do their jobs, don't be afraid to tell them. After you've made a good number of friends, of course.
You anger the wrong people and you will stay at the bottom for your entire career. You anger people by being candid about how bad working for TSA is to Management, and by criticizing those above you. If you manage to anger a passenger too much, they can also file a complaint that will stop you in your tracks. If you do a good job and people like you, you will move up, though. It also helps to pick up some extra duties and make sure you do a lot of work above your pay grade (LTSO level). You can get promoted, it's just a minefield.
Say goodbye to holidays.
Unless you've stayed with TSA a few years, you will never be fully in charge of your schedule. Holidays and work hours are bid on. When you bid is determined by your start date. If you're a new hire, you have to wait for everyone above you to move on before you'll get anything good. People who've been stuck in TSA that long, enough to build up seniority at the TSO level, are not going anywhere. Most of them either don't want to be promoted or are un-promotable. Once you get promoted your
Your probationary period is about 2 years long, if I remember correctly. Which means you can be fired for sneezing wrong for two years.
You will be verbally abused by a lot of people, and they wont be entirely wrong. You'll also get some really welcome praise. They also wont be entirely wrong. That's the job.