Learn English – A single word with the same meaning as: “Latest activity”

The word I would use is internment (as identified in the question), which Wikipedia describes as

the imprisonment or confinement of people, commonly in large groups, without trial

though I would not see it as necessarily going as far as the extremely negative associations of concentration camps from World War II.

For individuals rather than groups, I might use detention, which I would almost never use for being held before a trial (instead using remand) or after a trial (instead using prison).

This no doubt dates me, but we used to use:

doodly squat, also-doodley squat, also-diddly squat

1. a minimum amount or degree; the least bit (usually used in the negative):

"This coin collection isn't worth doodly-squat in today's market."

to mean the same thing. According to Random House, it goes back to 1934.

Merriam Webster speculates that it is:

perhaps an alteration of do one's do (to defecate) + squat

Dictionary.com says that it is:

probably euphemistic variant of doodly-shit, diddlyshit

It was considered "clean" enough for our 1960s era cheerleaders to use in the chant:

Our team is red-hot,
Your team ain't doodly-squat

And your sentence would then be...

They don't give parents doodly-squat.

Or

That listserv is only good for doodly-squat.