It's an entirely regional thing. Some places (typically the desert or semi-arid parts of the west) do it. Others don't.

My alarm system relies neither on power NOR telephone lines. It's got a battery backup and uses a cellular link to the monitoring company.

You can lock your panel. The power company if they want to cut you off will pull the meter. The fire department will either pull the meter or cut your lock.

In my area, certain repairs/renovations require that existing houses be brought completely up to current code. In instances where the existing electrical panel is in a location with inadequate (per code) working room, the solution may be to move all the circuits to a new panel. Often that location is outside. I share the concerns of the original post. A knowledgeable ruffian could also remove the meter.
A good welding shop can fabricate additional security bars to protect your panel. All that is required is to make it more difficult to get into the panel than into the house.
I put the ties on my garage doors. Then those posed a problem for me during a power outage. Possibly a problem in case of fire. My garage ceilings are almost 10 feet tall. A ladder and cutting tool should be kept at hand in such instances.

Here in Dallas it is very common to have outdoor main panels although we place it in the garage if possible. When we do service upgrades we have moved panels from closets, bedrooms, kitchens, you name it. Modern panels are easily padlocked. If you are conserned about access to your panel, have lugs welded to it so you can padlock it.

"Possibly a problem in case of fire. My garage ceilings are almost 10 feet tall. A ladder and cutting tool should be kept at hand in such instances. "

The panel cannot be high enough to require a ladder.

In may areas meters are still pulled by either the POCO or the FD for major structure fires.

It WILL be pulled if the place is no longer habitable as a safety issue after the fire (damaged wiring can be a secondary source of ignition, even after a fire is 'cold').

Without the correct gear, pulling a meter that is carrying a load MAY be hazardous.

Arc flashes are NOT to be trivialized and can result in significant injury if the correct gear is not used.

The current available from the POCO lines is VERY large (many tens of thousands of amps is routine).
The line fuses are on the primary side of the transformers (7,200 V is a typical minimum voltage) to protect the transformer, not the service conductors feeding your house.

Some FDs have gotten co scarred that instead of having the safety gear needed & learning how to pull meters they just wait for the POCO to arrive, or risk fighting a fire in a structure with energized wiring.

The gear is not all that much worse (or complicated) than regular turn out gear.
Mainly insulted sleeves, full face and frontal body protection, and sometimes an insulating mat to stand on.

The voltage available on a residence is normally only 120 V to ground.

Get a better quality opener. Some are available with battery backup. I defy someone to release the door on my jackscrew opener with a coat hangar.

A couple (actually at least three in most cases) pieces of sheet rock aren't a whole lot easier to compromise than many other doors, walls, or windows in most construction.

In my part of Louisiana almost all of the main panels are on the outside.

Here in Northern California, I have never owned a home, or recall seeing one, that didn't have an outdoor panel.

Now though, I'm thankful since our current home still has a Zinsco panel! Yikes!!

When I lived in NZ and Australia, the fuse boxes/breaker panels were commonly on the outside of the house. They had hasps for padlocks, but you had to buy them from the POCO.

If there's a fire in the panel, at least it's outside? Not sure where the practice originated in that instance. Britain?

"If there's a fire in the panel, at least it's outside?"

With the amount of power available from the POCO feed, having the box outside is not going to provide significant protection.

There is more that enough current available to blow holes through the walls of the box as if nothing much was there.

The various posts indicate significant regional differences. In most instances in my area, only the meter is on the exterior. In my opinion, that offers the better exterior appearance. While vandals can attack meters, it is rare as far as my experience goes. I saw one meter that had been smashed by a person who was not served by the electrical service in question.
Not wanting to offer advice to potential vandals, the outside panel offers all sorts of opportunities to the imaginative. So I avoid installing those if practical alternatives are available.

Indoor panels have a much longer lifetime in most climates. Most of the ones I have seen look pristine. I think the ideal might be a small main panel at the meter pan with one or more sub panels inside the house.

"There is more that enough current available to blow holes through the walls of the box as if nothing much was there."

If the panel is mounted on the exterior of a masonry wall, it seems like there would be less damage to the structure than if mounted near softer, flammable material indoors or out.

Even a typical residential masonry veneer wall (one wythe thick) is not going to stand up to a full blown arc flash well.

And frame houses remain a lot more common than even brick veneer, let alone actual masonry.

In that case, it is a good thing that we don't see full-blown arc flashes very much outside of youtube.

"I put the ties on my garage doors. Then those posed a problem for me during a power outage. Possibly a problem in case of fire. My garage ceilings are almost 10 feet tall. A ladder and cutting tool should be kept at hand in such instances."

Most people keep their tools in the garage so having a pair of cutters close by is not a problem. Just make sure family members know what to do. I can easily reach the wire tie on mine. Of course, having tools in the garage also works out well for the bad guys once they get in there. Makes it so much easier for them to get into the rest of the house. Adds insult to injury for the homeowners.

Upon closer examination I'm starting to see that moving the panel to the inside of the garage wall would be easy. All the wiring enters from the top through one conduit within the wall, so in theory it could be rotated around to face the inside wall and remounted without even having to rewire it (after cutting the power of course). I still need to check with some electricians and see about permits and follow-up inspections, plus how to re-stucco the outside wall.

If you decide to put a lock on the panel, even temporarily, see if your local police/fire departments offers a residential lockbox program. They're usually intended for senior citizens who live alone (to expedite entry into a house in case of suspected medical emergency without having to break down a door). That might allow you to lock the box but also allow first responders easy access to cut service in case of emergency.

My son bought a house in Tn. and its on the outside..I was shocked! Ours was in the basement and when we had work done the city made us move it upstairs into the house..cost a fortune! Outside seems like a terrible idea.

I was an electrician in Texas, I prefer an electrical panel on the inside, preferably the garage, who wants to open a panel and troubleshoot a fault during inclement weather at night, outside? Plus outside makes it an easy target.

Here's the answer: it's a money thing, it's faster and cheaper for the contractor to slap a panel on the outside of the house. It's a sign of our times, just look at all these "assembly line type" houses, most of the meter loops and electrical panels could be fabricated back at the shop, then simply brought to the job site and slapped on the wall, in "cookie cutter fashion" just like the rest of the house.

I don't know about that. You may be right that it's cheaper; I don't know. But I've seen outdoor panels on houses in southern states, and many of the houses weren't what I'd classify as today's quick and dirty Tinkertoy construction.

I think that having an outdoor panel is probably more local custom than anything else, but I could be wrong.

Moderate climate supports outside panel. Never had a panel outside in New England. All outside in SoCal and Seattle area.

David is all wrong there is no difference in price during construction. It's simply making a choice at the time of installation of the panel as to which way you mount the panel box facing outside or facing inside.

I'm not so sure about that. The codes that designate the location of the panel are very stringent. You must locate an area that satisfies the code. Then all your homruns change. In my experience the panels are located where the aerial lines drop. The electrician will locate the panel next to the meter because the feeder lines are expensive. I'm locking into this myself. If I pull the trigger then I will still need a jbox where the existing panel is located. At that point it's just as easy for the tweeker to cut power. Now the jerk just shut down my whole damn house instead of security lighting.