A recent thread about fire hydrants mentioned the pentagonal wrenches needed to open most hydrants. This got me to thinking: what other things are manufactured requiring custom tools to work with, expressly so Joe Public can’t tinker with them?
Is there a special tool to take the screws off of restroom stall dividers? I mean, if you look at them, you can see that they’re meant to be screwed on, with the regular slot for righty-tighty. But if a person were to try to unscrew - lefty-loosey - them, the screwdriver would slip right off.
The only way to open up an Agilent GC is with a torx screwdriver.
To turn water off and on at the street they use a pentagonal wrench to open the cover, pull out a T-handle about six feet long with a pentagonal socket on the end of it, and turn the valve open.
In other words, unless you’re good at toolmaking you’re out of luck trying to do it yourself.
My understanding is that those screws are meant to be permanent. If you want to remove the screw, you have to drill it out, or cut off the head, or something like that. I never have understood why a bathroom stall divider rates such measures. Was there once a rash of screwdriver-wielding perverts exposing helpless toilet users?
Diceman,
Ever seen a toilet stall missing its panels? Neither have I. See how good those special screws work?? 
Actually I agreewith you. I’ve always wondered how that got started in public toilets and why nowhere else.
Nowadays I see a lot of tamper resistant Torx fasteners too. Like a regular Torx but with a pin up the center that defeats ordinary Torx tools you could buy at Sears / The Big Box.
OP: Here’s a link to common oddball fasteners with some indications of which industries use them. http://www.lara.com/reviews/screwtypes.htm
Go to Mcmaster-Carr
Search under “Tamper-Resistant”. You can buy any kind of specialty fasteners, wrenches and screwdrivers known to man!
Some of my scope rings (Warne) use a goofy star-ish hex wrench to tighten them down. Not exactly uncommon among scope rings, but I dunno what advantage this delivers to the consumer.
Those bathroom screws you mention actually can be removed. I have a special drill bit/socket that grips the head and backs it out.
ANother special tool:
A screwdriver with two little dots instead of a blade. Look at some light fixtures and the panels on elevators for this little guy.
<hijack>I needed some security Torx last year to replace an ignition switch. I hied myself to the local AutoZone to pick up a set, but found their last one had been stolen. I found this rather funny.</hijack>
On the original tangent, some body plates on USAF aircraft are designed to open with a “snoopy tool”, so-called because it rather resembles a skinny Snoopy.
Tamper Torx, tamper hex (SAE and metric), tri-wing (think three legged-phillips), square, robertson, spanner (the two dots guy), clutch, butterfly-you can buy a hex bit insert set containing all of them for less than 10 bucks if you know where to look.
Try to take apart something assembled with an Oetiker clamp unless you have an Oetiker tool. (Without destroying it, that is) 
(Used in some automotive and self-contained breathing apparatus)
Air conditioning and fuel lines for the last 20 years have required a special set of release tools for disassembly. Heck-I’ve probably got over $250 worth of tools in the roller cabinet from when I was a mechanic/body repair tech that are so use specific it’s amazing.
Going back to the hydrant wrench-we only use the pentagonal type in the burbs. Urban areas now have a recessed triangle fitting that looks like the drive rotor of the Wankel engine. That change was effected to keep urban folks from opening hydrants in the summer time and killing water pressure. Anybody with a pipe wrench can open the pentagonal style.
Last of all-the blank fastener. When working for the bank equipment company, I’d occasionally have to pull the head of a night depository. To keep any friendly henry with a toolbox from performing the same feat with ease, we assembled them with blind fasteners. Spun in until finger tight, I’d then put an open end wrench to them, and they would shear at a prescribed torque value, leaving a flat surface you couldn’t grab with any tool.
Knowing the policies of the SDMB, I will not discuss removal.
Fords.
Seriously, didn’t Volkswagen make it impossible to replace the headlights of the New Beetle without taking it to the shop?
Are you sure it isn’t a Torx™ which is a very common tool? Hexagon star that looks kind of like a spur gear. Leupold and others use them. I can’t imagine Warne going to the trouble of making something proprietary that would leave someone stuck without the special tool. I couldn’t find that information on the website or a clear photo of a screw head but I’d bet dollars to donuts it is.
Many newer cars which have HID headlamps are not user replacement items. Also very pricey, feeding a high theft market.
The cleats on golf shoes require a special two-pronged wrench to remove and replace.
I checked on another site and Warned does use Torx screws. The advantage is that the screwdriver can’t easily slip out and damage other parts as a straight slot screwdriver can and it will withstand more torque than a conventional hex socket will in such tiny sizes.
Street signs are held on by big carriage bolts with a fancy four-sided angled-flat nut on the back side.
The nut looks like a pyramid with its top lopped off and hole in it. There ain’t no way you are getting a pipe wrench on that sucker. I learned of these fasteners years ago while reading a Popular Mechanics article, complete with illustrations. They even told how to remove them (you need another identical nut, though; just screw it on with the flats facing downward and you can put an adjustable wrench between the two).
As a one-time machinist, if I were faced with any of these fasteners in a situation where I had every legal right to remove it (e.g. on the industrial machinery I was fixing), I soaked it with Liquid Wrench and then I reached in the tool box for a center punch, made a starting dent as far off center as possible in the fastener, and then started whacking at the punch at an angle tangential to the fastener head – it usually came out. I guess this ain’t the solution for some delicate screw holding an electronic device together, though.
My friend, nothing is impossible when you have power tools.
Nothing.
I burn a lot of CDs every day. I keep a paperclip - a big one - with one ‘leg’ opened out as a wire tool. I rip that sucker down the shrinkwrap and tear it off.
I loves my CD shrinkwrap paperclip tool. Standard equipment at work.