At what point does a legitimately motivated activity become illegitimate when it is partially funded, without the participants direct knowledge, by parties that

At what point does a legitimately motivated activity become illegitimate when it is partially funded, without the participants direct knowledge, by parties that hope the activity will undermine others? Like, -- say there was a Save the Sea otter campaign that was pushing for closing down nuclear power plants because of their harm to the sea otter habitat (if this is actually a thing, sorry, I'm trying to make a silly example). This is a subject that reasonable people can differ on and it's very wholesome and within our tradition that people ought to be able to advocate for that. But then Russia hears about this and decides that getting rid of nuclear power would be bad for our economy, increase our dependency on their energy exports, and that the issue is the right mix of fringe and credible that it could become very divisive and distracting. ... So they massively fund it. Would that make the issue any less legitimate? Why? it's not the fault of the advocates -- particular if they don't know that its being funded for malicious reasons or they aren't personally the recipients of the funding. And if it doesn't make it less legitimate-- why would it be relevant to bring up in a discussion of the issue? It might be worth bringing up in the context of russian interference, but "our enemies fund this" isn't a particularly valid counter argument against the issue itself. ... particularly because the main motivation for malicious funding could be divisiveness rather than the advocated action itself being bad for us. If we did start to reject ideas because Russian funded promoting them then this would create an obvious vulnerability where they conspicuously fund the best ideas in order to kill them. You can't fight manipulation by doing the opposite of what it tells you to do since the manipulator can use reverse psychology.