In the USA. I don't know of any, and don't think there is any, legal obligation
for the WMF to comply with somebody who just says to them "please hand over any
information regarding me." One could still formally ask, say a typed letter,
certified mail it for effect, and maybe one would get an informative response. But I
don't think the WMF is required to. Politeness and professionalism requires them at
least to reply in one way or other, though not necessarily telling one anything.
The USA has the Freedom of Information Act, but I think that is only about information
held by the government. One can send a query in accordance with the FOIA and the
government is obligated to supply what it has, or say why not. But that wouldn't apply
to a corporation, private individual, or charity that keeps a file on one.
The only other way I can think of is a lawsuit. One could bring a lawsuit and then
subpoena the documents. But of course a lawsuit is costly to bring, and one gets in
trouble if it is frivolous.
Trillium Corsage
If you don't know of a policy which gives you the
right to ask
something, why ask that something?
Instead, ask something you know you have the right to ask; for instance,
EU citizens have the right, by privacy law, to ask what PII an entity
has about them.