Maybe I just don't get it, but aren't taxes levied when transactions occur? Since this is the case, isn't it too late? Much of the money this article refers to is sitting idle in offshore funds and therefore not subject to taxation. It's not even subject to the tax law of this land.
It is the financialized blood, sweat, and tears of generations of workers and it's just gone. However, crying over spilt milk is backwards looking and counterproductive to the building of a new future. Begging the robber to return what they took is weak and foolhardy. I dare say that this so-called group that is devoted to asking millionaires to please return their money is merely engaging in a rather elaborate publicity stunt for the PR benefit of their rich patrons.
So, unless the author is proposing we rob the robbers, I doubt we have much recourse in this matter. At this point, the reason the wealthy are sequestering their wealth from the economy is because capitalism works based on the principle of scarcity. Less money in the economy not only makes for less taxable revenue, but it also increases the value of the base currency.
There is no incentive for the wealthy to reinvest their wealth in the economy for the basic reason that it would only serve to devalue their holdings when inflation takes off as a result. Plus they would then have to pay transactional tax. This really points to the underlying sickness of the economy as the real problem no one has a solution for.
How about let's focus on building momentum behind the building of a green energy infrastructure? This would create a foundation for a new economic prosperity. This could be the alternative to a continued focus on reparations. The rich can spend their idle time plundering the past at their leisure. We the people can take the more creative approach.