Has there been any serious discussion of the implications of portraits? I couldn't find any with some cursory googling, but I'll be really surprised if it hasn't been discussed here yet. I can't entirely remember which of these things are canon and which are various bits of fanfiction, but:

• You can take someone's portrait without them explicitly helping, as evidenced in canon by at least one photograph of someone being arrested, whose picture in the newspaper is continually struggling and screaming at the viewer. I don't remember which book this was or any of the particulars unfortunately, but I'm pretty certain it's a thing that was in one of them. Or maybe one of the movies. Moving on.
• They can perform simple tasks of short-term memory and carry on a coherent conversation.
• They can walk from picture to picture to communicate with each other.
• They can operate simple mechanisms in some way. In canon, the door to Gryffindor Tower is a portrait, which requires a password before opening.

As far as I can tell, portraits in the Harry Potter universe would be a gigantic game-breaker if it weren't for all the other game-breakers overshadowing them. I suppose it's possible to mitigate this (maybe a picture carries less of the "person" compared to a portrait for which they have to sit for hours) but if that's not the case, portraits appear to be essentially a way of involuntarily uploading a copy of someone and enslaving them for all eternity, and all you need is knowledge of what they look like and a modicum of artistic ability.

edit: Oh crap, in MoR they ask portraits questions about knowledge they would have had before being painted, like "what spells did they teach you as a first year" and "did you know a married squib couple". So you're not just getting a basic "human" imprint, you're getting that specific person.

And on the flip side of that, not all the portraits in Hogwarts are necessarily real people. What moral weight does a newly-created personality in a portrait have?