Sorry, yes UK. I have the impression that Duolingo is predominantly based in/on USA and Lat Am usage, viz almost complete absence of vosotros forms. I guess that's why I didn't qualify my "we". In the UK the police often put "Police Aware!" stickers on crashed or abandonned cars, to save being rung up by everybody. "Known to" and "known by" don't seem to be predictable from "por". "Known by"is not unusual in UK.
As a native US speaker, I hear "known to the police" more than "by the police", so regional it must be
Could be regional. Native English Speaker from Philadelphia Metro (Cherry Hill, NJ), and it sounded correct to me.
SOUTHWEST, I have never heard to the police. I have heard They are known to run etc.
A euphemism to mean that they are "criminals" (= "delincuentes"). Used in both languages.
Por/para must be among the hardest words in Spanish to get a proper grasp on.
Por especially seems to be able to mean almost, but not quite anything.
Can this also be translated as "YOU (all) are know by the police?" DL doesn't think so and I'm wondering if I am simply missing something here
Yes Herb, you are right. "Son" like any other third person tense with any verb, could be used for the second person as "usted" form. So (ellos / ustedes) son conocidos por la policía, is correct depending whom you are talking to. (corrections are welcome)
I got marked wrong as well when saying "you all" although I think it's also correct.
Here we usually say "they are wanted by the police" but wanted would be quieren and this isn't that. I got it wrong.