Concern trolling
Etymology
An internet coinage of the 2000s combining “concern” with “troll,” the online provocateur (itself from the fishing term “trolling,” dragging bait, later merged with the folkloric monster). The concern troll poses as an ally offering advice while actually sowing doubt.
noun · /kun-SURN TROHL-ing/
Pretending to support a cause while raising “worries” designed to undermine it.
What it names
The disguised attack that hides opposition inside a mask of friendly, helpful concern.
Example
“I agree with your movement, but this protest will just turn people off” can be sincere advice — or concern trolling.
Related idea
Concern trolling fakes sympathy to weaken a side; sealioning fakes polite curiosity to exhaust an opponent, and the motte-and-bailey retreats to a defensible claim when pressed.