Can confirm on the way back from Hawaii 6 months ago, my bag got searched. It was a suitcase with a combination lock inbuilt into the zipper. I didn't know it was searched until I got home because they locked it after searching it. It was so weird to find the piece of paper inside under my clothes saying they searched it.
Have had mine searched before also -- two instances worth mentioning:
1. As mentioned in a previous post, I usually plastic wrap my bag for protection of luggage both material and so it isn't pilfered by ground crew (have had this happen), when searched TSA unwrapped the plastic, searched and put the dirty plastic wrap inside my bag ... thanks!!! Guess they can't keep it ?!
2. As
@Gareth suggested TSA insert a standard piece of paper indicating the bag was opened and searched, they found it appropriate to place this inside a note book that was about 300 pages of paper. Suffice to say I was not aware my bag was searched for sometime after arrival home. TSA are special people.
And for further interest, this didn't happen to me, but a friend; her luggage was searched and TSA located a set of earphones she'd lost years earlier that were stuck in the inner lining of the case. Random!
~c.