I was traveling with my usual mountain of gear in my pack, on my way to LHR and, having been trough WTMD and my gear through X-Ray, I have the following conversation:

TSO: I'm going to need to look though your pack.
Me: That's fine, just change your gloves first.
TSO: (stops, looks at me with mild disgust) If you prefer, you can go back to the end of the screening line, take your pack apart yourself and put everything through the X-Ray again.
Me: Why would I do that? I'm through, my suitcase is through, and you want to look in my bag... all I want you to do is use clean gloves.
TSO: Well, I'm going to swab it.
Me: Fine.

Said TSO takes my pack to a swabbing station that, contrary to the admonition posted on it, is being used by a pair of kettles to stack their possessions while they reassemble themselves following screening -- that includes Pa's shoes.

Me: If you're going to swab it, could we use a sterile station? There are three open and this one is clearly no longer sterile.
TSO: <insert a repeat of the conversation about me going to the end of the line here>

So, he takes my pack to the supervisor's desk. I follow.

TSO: This guy seems to have some sort of problem with me doing my job.
Me: I have no problem with him doing his job. I simply requested that he change his gloves before handing my gear and that he uses a swabbing station that hasn't been contaminated by pax stacking their gear all over it. I don't want a false positive any more than you do -- (to the TSO) I am assuming you don't want a false positive...
Supervisor: (to TSO) Why don't you just use one of the other stations?

Now fully disgusted, he takes my pack to a sterile station and proceeds to spend thirty minutes (not an exaggeration) feigning amazement at the contents... minutely examining each article as if he had never seen an iPod or headphones before. An observer would have thought he was trying to swab my pack and its contents clean. Everything is then sent through X-Ray.

As I repacked, he remarks that I should simply take everything out of my bag next time and should know better. I suggested he should volunteer for retraining if he doesn't understand how to keep his workstation sterile or that a request for a change of gloves is a reasonable one.

By the time we were done, a new supervisor was at the desk and I requested a comment card. Handing it to me, the supervisor says, "I hope it's a good comment." I responded, "You'll have to ask (pointing) him about that." Card in hand, I smiled and waved to the TSO.

The comment card is in the mail.