The user can create a flag. You need to be very careful about its creation, and understand what purpose the flag is intended for.
The flag itself cannot be removed in the future. If the person who created the flag renounces it, i.e. withdraws their support, the flag can still remain if other users supported it.
For the flag to cease to have its power, there must be support in the opposition.
For more details, read:
Trust flagsThat was the answer I needed, and thanks for the reference too, @lovesmayfamilis.
So far I haven't flagged anyone for any case I've encountered around the forum, but I'm more inclined to support or be in opposition if the accusations are not true. Well maybe out of ignorance of small details, but in general I know how it works.