I wouldn't lock them, they do go into your suitcases.. and for the same reason don't put anything valuable.. Because its not uncommon for things to go "missing"

You can lock your suitcase as long as you use a 'TSA' lock ; security officers can open them without destroying your luggage.

http://www.tsa.gov/travelers/airtravel/assistant/locks.shtm

I went to NYC last month and did not have any issues with my locked suitcase

On the way back from the US this summer, one of my suitcases got searched.  Luckily, I had those TSA locks (you can find them here in CH as well).

The TSA even left a note saying that they went through and are sorry in advance if your non-TSA lock got destroyed in the process.

Worth the price.

Cheers,
P.

I go back and forth several times a year. Mine get searched every time, coming and going. I normally go through Newark on Continental, but have made other multi-leg trips on other airlines and my bags get searched every time. They leave a notice stating that they have inspected your baggage.

I wouldn't waste the time, or the cash on a lock. They are going into your bag whether you like it or not.

Not to insult anybody or start an argument, but i can't really fathom why people put up with this... Any country that disrespects my privacy like that makes sure i will never visit it.

Well said Paul. I agree with you 100%.

I think the bags are being scanned first and if they have any doubts about the content, they'll open it.  I don't think they have the staff and time to search every single bag...

As for the locks, the TSA officers are not the only ones handling your bag in an airport...

"They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety." - Benjamin Franklin

Once again, I agree with your opinion.

Any fool can criticize, condemn and complain and most fools do.
Benjamin Franklin

And I agree that I disagree. Some just don't enjoy beeing treated like a criminal, at least i do. And i do not agree with most TSA or airport policies, i always *politely* voice my disagreement whenever i am asked to remove my shoes or have a pat-down. I never fly to the airports that have the new backscatter scanners and don't visit countries where the airport "authorities" have too much power in my opinion. But this is my stance, and you are free to disagree.

I respectfully disagree with your stance. You aren't being treated as, or considered a criminal. When you choose to fly on a public carrier, you and everyone else flying on that flight must adhere to TSA rules. It's as simple as that. As Paul stated earlier, it's for your own protection. If you disagree, that's fine. You have choices - fly, or don't.