There is a long list of over the counter medication you can legally purchase, but cannot take it into another country.
Changing your own light bulbs; in Australia, the law says you must hire a licensed electrician to do it.
In my state (CT) it’s illegal to sell pickles that don’t bounce.
You have to know how to play an accordion in North Korea to be able to teach.
Chico, CA, it’s a $500 fine to make or have a nuclear weapon within city limits
“No person shall produce, test, maintain, or store within the city a nuclear weapon, component of a nuclear weapon, nuclear weapon delivery system, or component of a nuclear weapon delivery system under penalty of Chapter 9.60.030 of the Chico Municipal Code.”
In Texas, there is still a law on the books that it is a crime to carry bolt cutters around. It is a leftover from the days of cattle rustlers, when the bad guys would use bolt cutters to take down barbed wire fencing. Pretty sure it hasn’t been prosecuted in a hundred years.
You can go to Lowes and buy weed-killer off the shelf and use it on your property. You can use it on your parent’s property. If you use it on your neighbor’s property and he gives you $20, that’s a felony.
Edit: Treating according to label instructions for friends and family without compensation does not qualify as a business activity most places. If you do this and receive compensation, then you’re conducting business and under the law you should have a commercial applicator’s licence. This is mostly an example of a badly- written law that is too open- ended. I don’t know anyone who has got in any real legal trouble over an unlicensed jug of roundup, but they could.
Having a lobster of a certain size in your possession.
California Law stating that it is illegal to wash your neighbor’s car without their permission.
Also, in San Francisco and Long Beach here you cannot store anything other than an automobile in your garage.
Edit: This is no longer a law/ordinance in Long Beach anymore.
The SF one is for commercial structures only, but at one point it definitely was illegal to use your garage as anything other than a parking spot for your car. People could do stuff like rent out their garage, tax free.