I am not a crook.

October 2, 2005 11:49 AM

Why do I set off certain security alarms at the entrances and exits of some department stores?

I set off security alarms when I walk through the front doors of certain stores--Walgreens and Target in particular, and not at all at other stores with similar anti-theft alarms posted at exits. I've ruled out the metal in my belt, various and sundry types of shoes (it happens when I'm wearing flip-flops), there's no metal plate in my head... I figure it must be something in my wallet--but what? I'm tired of getting that look from cashiers and security guards.

posted by hamster to Grab Bag (18 answers total)

My digital camera does it occasionally.
A prankster could have put one of those RFID tags in one of your coats.
posted by weapons-grade pandemonium at 11:55 AM on October 2, 2005

Do you have a proximity card or any other doohickie that you use to unlock doors? I've heard those can set off anti-theft devices, although I've never had that problem myself.
posted by stefanie at 11:57 AM on October 2, 2005

Assuming you are wearing different clothes each time and don't have a schoolbag or something that you always carry, is there anything in your wallet that could contain an RFID tag? (e.g. like this (the antenna doesn't have to be laid out in a square, it can be a long skinny rectangle, for example).

Is there a store where this happens you might be able to get some co-operation/patience from the staff? Stand by the sensors and take your wallet in your hand and put your hand through the sensors. If the alarm goes off, start taking things out of the wallet and testing them individually.
posted by winston at 11:57 AM on October 2, 2005

My younger brother had this problem for a good span of 2 years. We eventually figured out it only happened when he was wearing his favorite coat. Said coat had an anti-theft tag embedded -inside- it's lining.

I am willing to bet your situation is similar. Take stock of what you're wearing next time.
posted by zerolives at 12:12 PM on October 2, 2005

This happened to me for a bit too. Turned out to be a building access card in my wallet with an RFID tag in it. I found that if I was careful and walked exactly in the middle of the two sensors (i.e., as far away from both of them at the same time) I would be far enough from either one to avoid setting them off.

The other solution was to take my wallet out of my pocket and hold it above the sensors while I walked through.
posted by epugachev at 12:55 PM on October 2, 2005

Another vote for the security badge for work. I used to have one and set the alarms off all the time when I had it with me. Like epugachev, I started holding it above the sensors when walking through the doors. That was less embarrassing than setting the darn things off.
posted by schnee at 1:43 PM on October 2, 2005

Does any of your clothes or your wallet have one of those hidden sticky metal/plastic things in them? The things that they deactivate at the counter of the store where you buy it, but they might still be active elsewhere?

I've had a purse that made me beep 80% of the time, until one time a random store (where I hadn't bought it) demagnetized it again, and since then I've been beep-free with it. So maybe it's something in your coat/wallet/bag that you usually carry around. Just ask any store (when it's not busy) to demagnetize all your stuff.
posted by easternblot at 1:46 PM on October 2, 2005

Work security badge does it for me all the time. Then I take off sprinting.
posted by yerfatma at 2:12 PM on October 2, 2005

I read somewhere that a large percentage of these false positives were due to people with wallets that still contained the original antitheft device from when it was sold. Apparently in some wallets they insert the thing (the thin foil piece with a funky pattern) in some really obscure place in the wallet and most people don't find it. Try taking absolutely everything out of your wallet and looking under as many flaps/seams as you can.
posted by Rhomboid at 2:29 PM on October 2, 2005

I wad told by one places' security that it was my cell phone that did it, but I never quite bought that.
posted by tristeza at 3:02 PM on October 2, 2005

My wife had an rfid thingy buried in her purse!

It was really annoying because we were in Portugal (as you do) and couldn't speak the language. Having the alarms ring whenever we went into a store was pretty embarrassing.

Anyway, a local managaged to find it buried behind some cloth.

Problem Solved.
posted by viiviiviivii at 3:33 PM on October 2, 2005

I did this for ages, until as Rhombold says, I found a little tag hidden beneath a tiny flap in my wallet. Problem solved. If you're a guy, look carefully through your wallet, money clip, cell phone holder. If you are always carrying a bag, seach through the entire thing to find the tag. It'll be there!
posted by fionab at 4:11 PM on October 2, 2005

Possibly this? (gratuitous green-to-green self link)
posted by Pinback at 4:18 PM on October 2, 2005

My mom's cell phone sets them off.
posted by puddinghead at 6:13 PM on October 2, 2005

I have a theory about a certain music shop that I buy gear from. As I look er, unconvential (unshaven, casually dressed) every time I walk in there it goes off. I think they set it off manually so it gives me a jolt and possibly discourages me from theiving or lets them search me as I leave when it goes off again. It really gives me the shits. The only reason I think this is that after a purchase, when I actually have something that may be protected, it doesn't go off. It has also happened to me in a book store and a supermarket.

Or I could be just paranoid
posted by bdave at 7:55 PM on October 2, 2005

Response by poster: Sure enough, I found an RFID tag hiding in a very obscure fold in my wallet. Thanks, everyone!
posted by hamster at 8:00 PM on October 2, 2005

I used to stick those in my roommate's pockets just for fun.
posted by Sallyfur at 8:51 PM on October 2, 2005

The anti-theft widgets in your coats, wallets, CDs, books, etc. are NOT "RFID" tags.

RFID is a much different technology, used to track and locate individual items. The tag could be carried by a person, like a doctor in a hospital, or a piece of gear that you would like to keep tabs on, such as a portable sonogram machine (again, in a hospital). RFID technology isn't currently used for loss prevention so much as keeping track of what you've got and where it is. Check it out. (I'm not related to that organization, it just showed up close to the top on Ask.) Unlike the anti-theft thingies used at the Wherehouse (which are sensed only at the doorway), RFID can be used to locate a specific item anywhere in the office building, hospital, or... uh, warehouse.
posted by fuzzy_wuzzy at 9:42 PM on October 2, 2005