My international gate screening experiences:
LHR: random at the UA gates (on at least my 8 flights this year)..don't remember seeing it at AA gates
FRA I've never seen gate screening on UA or AA flights
SYD is mandatory for everyone (UA)
YYZ/YVR have never seen it
ZRH arrived to boarding area late (AA flight) but appeared that everyone was screened

CDG asks the questions to everyone in the jetway. Some get gate screened.

Canadian airports stopped this practice about two years ago.

For AA, it happens in the gate lounge area. It's unusual for business or first class passengers to be selected for this additional and unnecessary harassment. Usually there are 4-5 tables of harassers.

I would be very tempted to announce in the loudest possible voice, "I was already screened by TSA at the terminal. That should be sufficient or, is that screening not good enough for you?"

Do it. Passengers should put up a lot of resistance to this disgusting harassment. Make them change their gloves, even if they claim their gloves are new. They don't trust you, why should you trust them? If you can save even one person from this sick and unnecessary harassment, then such tactics are worth it.

Who knows, maybe the screeners will see how disgusted the passengers are and quit this un-American agency?

Rather than showing "vigilance", this looks like "Couldn't you do it right the first time?" to most passengers. Another brilliant idea from TSA HQ that's backfiring, but they either don't (or won't) realize it, or don't care.

Also Random at AA gates.

However, if you jump over to LGW, you have the full ICTS question and answer game with the US carriers plus random or mandatory search; seems to vary depending on flight, day of the week, whether it is a full moon, and of course, changing politics. Always a random search at minimum.

I disagree. When it was "reduced," it practically disappeared. IIRC, its re-appearance began around the time of the widely discussed "surges" last year (or early this year?). It has most certainly "restarted."

Several weeks ago in PHX I watched the TSA screeners set up the "harrassment tables" near the jetbridge door about 30 minutes prior to boarding. Three or four screeners then stood at them like statues until boarding was announced. This occurred at Gate 2, which wasn't 50 yards from the TSA checkpoint.

The good news is that many passengers wondered aloud why the TSA felt the need to re-screen them given that they had just passed thru the checkpoint minutes earlier. Some passengers had very un-charitable things to say about the constant "you're always a terrorist suspect" attitude. Some comments about the "wasteful government agency" and "they must be overstaffed" were heard. ^

Amazingly, the wheelchair passengers were boarded with no gate grope. Then First Class was called, again with no gate grope. Having boarded at the end of First Class, I can only assume that the coach passengers were the intended victims.

The AA gate agents made an announcement about the random gate screening and asked everyone for their "full cooperation" with this "important security function" and other apologist tripe. No doubt these guys go bowling with the screeners.

Does TSA enforce its liquid policy when they do gate screening? After the initial screening, a lot of us take the liquids out of our freedom bags and put them in our purses or backpacks. Do you get a chance to put all of your liquids back into your freedom bag, especially if this is a surprise gate screening? What about the liquids and drinks that were bought beyond the initial TSA screening point?

Which would meet head with my intractable insistence: "No gloves, no looksee. I'll wait."

Liquids purchased in the sterile concourse should not be confiscated during gate screening. Gate screening is pretty rare, but it appears during the holiday period they beefed it up at some locations.

..but how about empty bottles carried through the initial screening and refilled once airside?

How are the gate harassers going know where the bottle was acquired? Detective work (or critical thinking) isn't exactly their strong suit.

uh, Spiff, don't you mean detective work and critical thinking . in the this scenario, the terms are not mutually exclusive.

When you work in an airport, as I do, you probably see about everything. I've seen people look as if they were moving via the airlines! I think for most of the people who spend time in airports, the only thing they want TSA to do is pick up everything and leave and that's just not going to happen. It crossed my mind a few days ago, that we have been fortunate not to have had the bombings on our subways and other transportaion systems that London and Madrid had. Maybe some of the things that are considered harassment has been of some value. Just because we don't always agree or always understand it doesn't mean it is always a waste or that they are stupid. You must have at least 50% of people getting in to the security lines copping an attitude...before they have even come face to face with someone from TSA. Remember our government gave 6 billion dollars away to keep people from filing suits related to 9/11, because someone wanted to hang the blame on Argentbright..that they were not doing a very good job of screening. TSA is probably doing as much, if not more and something else were to happen, who would you blame then? The last time you had a happy travelling public, was the last day before the first checkpoint ever went up anywhere. But you also have some people who intentionally make it harder for themelves and others indirectly.