> It's an awesome idea, because it brings the painful past right into our daily lives. You're forced to serendipituously "stumble" across them every now and then.
I very much believe that this is the intention, but does it actually though? Oppressive country frequently brings up the past as a safe way to legitimize the present. Russia seems to have had an increase in this in recent years as it now started a war in Europe. Most of the western world seems to not have learned much at all from the second world war and are yet again running black sites, funneling money to regimes and fighting wars to defend some of them.
Unfortunately I think part of the popularity of these stone today is that they are no longer provocative. Their existence doesn't seem to have the effect of for example highlighting still exiting companies participation in the holocaust, current day trade policies or crimes against humanity. Putting one of these outside a company, judge or commander involved in past or present atrocities would probably result in it quickly being removed and you potentially landing in jail.
But I guess that even if few learns the bigger lesson they might still be a net positive.