In several papers where the author is listed only as V. Desai, and ownership has been claimed by a V**** Desai who is known to NOT be the author, how should this be flagged ?
Best to contact the individual directly and ask them to stop and retract. If they persist (as it is a breach of academic integrity) you have recourse to approach their employing institution - as well as editors of journals/ResearchGate etc - to highlight fraudulent behaviour.
In the 3 cases where I tried, contacting the individual was futile, but I did not carry it any further as these are colleague identities, not my own. (It's exploited frequently when authors use only initials instead of full names) Had hoped ResaearchGate had another way of accessing the feature where it asks ~ "did this person author this paper with you ?", which seems to solicit this sort of information, but have found no path there. Unknown if they act on those inputs, but seems like there is at least the start of a mechanism there.
RG tries to find the closest match. If someone claims it as theirs when invited - even if it is not - that is probably the end of the trail. I don't recall being asked - 'is this an author you recognise' - but then I have not personally come across this before.