If you're transiting at DOH and flying to the US, you have to go thru a second US-specific security check. Be very afraid of this checkpoint, especially if you are not white or Arab. Here are the things you need to know.
* They will throw anything that they deem unacceptable into a large trash container near them. They do not inform you of this or give you a chance to say, empty your water out of your baby's bottle, they will throw the bottle away (happened to us).
* If you complain about the missing item, everyone will look away. No one will help you.
* If you ask for a manager, a Qatari official is pointed to. This guy will listen to you for a half second and without a word turn your back on you! When called again, he will threaten to cancel your ticket and "send you back to Hindustan".
Googling led me to this post where the guy, seems to have run into the exact same official:
http://www.flyertalk.com/forum/qatar...r-airways.html.
I have no complaint about Qatar "Airways". But Doha Airport, and by extension, Qatar, is a place I would be scared to visit again.