I see a lot of "banned from", but it seems to be rarely used in some context. I am trying to figure out why.
I see a lot of people say "Tiktok was banned in the U.S.", but not "Tiktok was banned from the U.S.", yet I see a lot of people say "banned from the U.S." Why is it rare to hear "banned from" in some context? I keep using them interchangeably.
If something (or someone) is banned in a place, that thing is not permitted in that place—it is not allowed to be inside the boundary.
If something (or someone) is banned from a place, that thing is not permitted to go to that place—it is not allowed to cross the boundary.
So only something that can move, or something that can be moved, or something that can be carried, can be banned from a place. More often than not, even things that can be carried would use "in" rather than "from." You would say "Joe is banned from Bob's Bar" but probably "Knives are banned in Bob's Bar." You would definitely not say "TikTok is banned from Bob's Bar", because TikTok is not a physical object that can be carried into the bar.
The distinction is a subtle one, but if you use it wrong it will be noticeable to native speakers.
randomhead's answer explains the difference very well. To illustrate the two meanings:
Salman Rushdie is banned in Iran.
This means that it is illegal to own or sell the works of the writer Salman Rushdie in Iran.
Salman Rushdie is banned from Iran.
This means that Salman Rushdie is forbidden to visit Iran.
In both cases, we have a form of the verb ban plus a prepositional phrase. In both cases, we're using ban to mean “prohibit especially by legal means.”
In the case of banned in, the preposition in describes the location of the ban. Banning is done through some rule, law, decree, or so on, and that that act has a limit. The prepositional phrase simply describes the limit or location of the ban.
“Tiktok was banned in the U.S.” — Tiktok was banned. Where is that ban effective? In the U.S.
In the case of banned from, we're using the preposition from as “a function word to indicate physical separation or an act or condition of removal, abstention, exclusion, release, subtraction, or differentiation.” So in this case we're emphasizing that the thing or person being banned has been removed or excluded.
“Steve was banned from the bar.” — Steve was told never to enter the bar again. The bartender may have his photo next to the register. Steve may have been physically ejected by a bouncer.
Banned from is only really used for physical things, because it implies separation, so something must be inside and something must be outside. It's most often applied to people, because there's the aspect of exclusion and differentiation — there's an in-group and an out-group.
To get to your question: If we say “Tiktok was banned in the U.S.,” we really mean the use of Tiktok's service was banned. There's no physical Tiktok, so we wouldn't use banned from. If you were to say “Tiktok was banned *from the U.S.,” a listener would probably try to find some way to match the word “Tiktok” to something physical — perhaps they'd imagine that the company had a U.S. office that had been shut down and banned, or that the company's executives had been banned from entering the U.S.
To be "banned in" describes the jurisdiction to which a ban applies. To be "banned from" describes the zone(s) that the ban applies to within that jurisdiction.
In many cases, the scope is the entire jurisdiction:
A ban in Bob's Bar bans Joe from Bob's bar. Joe is banned from Bob's Bar and he is also banned in Bob's Bar, but your use of preposition determines if you are talking about Bob's Bar as the jurisdiction or Bob's Bar as the exclusion zone.
But sometimes it its not:
A ban in the United States bans Joe from entering any Bob's bar. Joe is banned from all Bob's Bars in the United States, but he is still allowed to be in and do other stuff in the United States even though the ban applies to the whole United States.
This also applies to less tangible things:
A ban in TicToc(*) bans Joe from TicToc. Joe is banned from TicToc and he is also banned in TicToc, but your use of preposition determines if you are talking about TicToc as the jurisdiction or TicToc as the exclusion zone.
or:
A ban in the United States bans Joe from using TicToc. Joe is banned from using TicToc in the United States, but he is still allowed to be in and do other stuff the United States even though the ban applies to the whole United States.
There are also some weird cases where a ban zone extends outside of the jurisdiction (because some politicians are that cocky)
GDPR is a ban in the European Union that bans anyone from saving an EU citizen's PPI without encryption. So even an American is banned from saving an EU citizen's PPI without encryption, but GDPR is a ban that is only in the European Union.
(*) This would be an unusual thing to say, but still grammatically correct. A program or system can contain a ban in its code or rules. So you can be banned in a non-physcial jursidiction.
