Are there any online community investigations of PhD thesis plagiarism outside Germany? In Germany there is a wiki-like webpage that investigates PhD theses for plagiarism: http://de.vroniplag.wikia.com/

On this webpage PhD theses that are suspected of plagiarism are investigated by an online community. Anybody can contribute in an anonymous way. For the thesis manuscripts that are investigated there is an indication of plagiarized text for each page.

My question is: are there any such initiatives in other countries?
And would that make sense?
I am not aware of initiatives in other countries. However, while VroniPlag started out with examinations of German doctoral theses, it is no longer limited to those. Today, it investigates suspected plagiarism in PhD theses written in Spain, Ireland, Denmark, the Czech Republic, Austria, and Italy. To the extent that this is a continuing trend, VroniPlag already is an international project.

So the answer to the question in your title (which differs from that in the body), whether online community investigations of PhD thesis plagiarism outside Germany exist, is yes.