Practical Travel Safety Issues - How worried should I be about obviously hacked electronics?

I have a cell phone whose USB port broke. In order to fix it, and to make it more practical to me while I was at it, I replaced its broken micro-USB port with a full-size one. Because that could not physically fit inside the phone I melt-glued it to the side, with wires going into the phone through the hole left by the old broken port.

This is perfectly functional but aesthetically very obvious, as you can imagine. I'd like to bring this phone with me when I travel abroad, but I'm afraid that airport security might think it's... some kind of bomb, I guess, and not allow me to bring it onboard.

The phone works fine, and I can show to the staff that the attachment is merely a USB socket by plugging in a thumbdrive, or something, but I'm not sure how much help that'll be.

Should I be worried?

Welcome to flyertalk.

I've personally never had anybody even look at a cell phone, so I would say you should be fine. Make sure you can power up the phone, and they should be fine with it. If they do pay any attention to it they may do a swab of it, which you should have nothing to worry about.

Thank you, that reassures me :)

They may or may not take a closer look. I had a laptop power supply that I repaired (had to open the case), so it had tape around it and silicone to form a homemade strain relief.

The TSA at one airport insisted on testing it with the ETD.

I would be leery of security contractors in non-US airports that are concerned about modified devices.

The phone works fine, and I can show to the staff that the attachment is merely a USB socket by plugging in a thumbdrive, or something, but I'm not sure how much help that'll be.

Should I be worried?

Welcome to FT. In all likelihood, you will not have any trouble. However, there are plenty of horror stories on the web about passengers being harassed over customized electronics and/or having the device confiscated. Fortunately, these incidents seem fairly rare. And honestly, I think most of these incidents are triggered by power tripping screeners which would find something to set them off even if it weren't for the electronics. These are the same class of people who freak out at breast pumps and recently chewed out a FTer for having a scrap of paper is his pocket.

What I would do if I were you is place the phone in one of the gray bins, pretty much by itself, but with something lightweight on top of it, like a jacket or a full-page boarding pass. That does three things: 1) It makes the phone easier to see on the x-ray and less likely that the phone plus some adjacent object will look like a cartoon bomb or some other weird thing (e.g., http://www.flyertalk.com/forum/16890440-post13.html) 2) It separates the phone from your other items so that if they want to examine it they don't have to dump your carry-on bags in the process, and 3) It obscures the phone from (non x-ray) view, preventing some screener from catching a glimpse of it and freaking out.

If they want to swab it for explosives (i.e., the ETD swab) after seeing it on x-ray, that's fine and fairly routine. Ask for them to use a clean swab.

Personally I've never had any problems in my handful of travels with custom electronics, though I've probably been lucky. In 2006, I flew with a laptop with a small ribbon cable coming out of the case and a homebrew circuit board fastened to the case connected to that cable. Never got a second look. I've flown several times with a Pelican 1520 case as carry-on full of amateur radio equipment including antenna wire and large coils. The equipment gets swabbed usually but there have never been problems. And I've flown a number of times in the last year carrying this little home-built transceiver ( http://www.humboldt-arc.org/articles/transceiver/k9acradio.htm ) as well as an AA battery pack and a bunch of antenna wires with it. That's yet to get a second look too.

If you do run into any trouble, try to remember that you have not done anything wrong and stand your ground. Don't apologize. Don't let them confiscate something that is not an actual prohibited item. Don't act like you're in a hurry even if (actually especially if) you are on the verge of missing your flight. Do ask for supervisors and/or law enforcement officers if a screener wants to do something absurd. Remember that the screeners' power derives from passengers feeling hurried and therefore caving into their demands, no matter how silly, in order to avoid being delayed. A non-rushed passenger takes away the vast majority of TSA's power, and it can actually be quite comical to see TSA's behavior when they don't have that power.