I would think that this scenario could be considered either “disturbing the peace” or “disorderly conduct.”
Do the other Germans here agree that committing an act that is somewhere between dickish and criminal is humorous?
In the US, your angered victim may well be carrying a firearm.
For all of you objecting to the “more deserving” term:
Whhhooshhhh!
I’m frequently reminded that the average age of the SDMB is “coot.”
When* I’m* in Tesco’s I often wish to crack a whip brandishingly and scowl: “Back, Back You Dogs !”, glaring at the canaille. Still more so than elsewhere. Most supermarkets have the charm of morgues.
Tesco more so than others.
As, to misquote Lord Haldane, a ‘spiritual German’, I think describing it drolly is.
I’m going to need a cite for the idea that Germans have a sense of humor.
no it wasn’t. First rule of comedy is “know your audience.”
Okay, now I’m going crazy. I’m SURE I read an article around Black Friday 2014 where the author asked legal experts about the status of taking an item from someone’s shopping cart, but I can’t find it for the life of me. I thought it was on Slate, but who knows?
If someone “liberated” an item from your shopping cart, could you get away with pulling out a gun and shooting him while claiming self-defense? Outside of Texas, I mean.
While probably not against the law, you would be stealing the other person’s time. They took the time to locate the item and put it into their trolley. As the item was the last of its type in the store, if the person really needs it they are now required to go to a different store. Even if it had not been the last, they would still need to retrace their steps to get another one.
Not exactly a capital crime, but it would certainly be a dick move.
No idea about the legality, but anyone who took the “far more deserving” bit seriously after also reading the “lawful good” bit can’t really criticise anyone else’s sense of humour…
A pure guess here, but I’d imagine that the item in question belongs to the store, so their representative would have the right to decide who, if anyone, gets to purchase it.
This is an old George Carlin routine - “It’s not yours YET”.
I have had people take the whole cart before by accident, and an empty cart when I’m shopping and have not put anything in it yet and walk away for a second.
It looks like disturbing the peace is a subset of disorderly conduct.
The purpose of the “disturbing the peace” crime as stated in my link seems to fit very well.
I certainly think that purloining someone’s groceries would tend to lead to “disorder and chaos” and would definitely disturb my peace if I were the purloinee while tending to my “personal affairs” of shopping.
[I believe “disturbing the peace” is called “breaching the peace” in the U.K.]
Deliberate.
I’ll refrain from hypothetical moral judgements, but I will note that if such an incident were to happen, and if it were to lead to a dramatic confrontation between the shoppers, and if I were to witness all this, I would find it . . .
. . . entertaining.
In the UK at least, the supermarket owns the goods until a contract to purchase has been made between two parties and the contract has been fulfilled. Up until that point the supermarket has total control over the item, able to decide totally freely how to dispose of the it, choosing one or the other, choosing neither, or even auctioning it between the two people.
If the disagreement between the two people became heated, either or both could be charged with a public order offence.
I take my mother to the commissary at the local Air Force base occasionally. They have signs to put on your cart that read “Still shopping”. You’re supposed to write in the time that you left the cart, but I’ve never seen anyone do it.
There’s always the Solomonic solution.
There was a comedian who advocated, for men, to speed up their shopping, and be certain to get the best produce, (while lacking all knowledge of how to select such), simply wait till some woman turns away and liberate their produce items from their cart!
The reasoning being, he’d watch a woman spend 10 mins choosing a tomato, and decided that’s the kind of knowledge you must be born with! 
It’s not a crime. There is no conversion - since the “victim” is not the owner. If you took it out of somebody’s hands, it would probably be a battery.
These are both names for catchall laws described by statutes tend to vary quite widely between jurisdictions.
I work in a grocery store. You’d be surprised how often a customer simply walks off with the wrong cart, continues their shopping, and doesn’t realize until much later that there’s a whole bunch of stuff in “their” cart that they didn’t put them.