Why is it any business of those who are NOT in charge of this campaign, NOT associated with IGG, have NOT invested in this venture to reach out to anyone who is involved in this venture as a funding participant? If I were a CF campaign funder, and I did so willingly, as an adult, which I'd have to be to join in the first place, I would most certainly NOT want some person or persons on the Interwebs to interfere or attempt to interfere in my crowdfunding choices.
If you have a legal issue then pursue a legal course of action and leave the individual funders out of it. If it were me and anyone attempted to contact me without invitation to do so, to 'warn' me about the grave error of my ways in making my funding choices, I would consider that harassment and would seek a remedy for that.
I found your questions about "who would do this and why" to be interesting, so I thought of a few replies, depending on who you are and what your stake is in all this. People don't do things without reason, even if it's a reason you aren't aware of.
E-bike aficionados - the e-bike is relatively new outside of China, and e-bike riders around the globe are facing a lot of legislative and public flak for their hobby. It makes sense that someone would not want their hobby (and themselves), to be trashed before the public by the likes of Ivars.
E-bike dealers and repair shops - a dealer would not want their product's reputation, or their business, to be damaged by public perception of the Ivars Dog & Pony Show.
Ivars backers/customers - it's humiliating to realize you just handed a chunk of your money to a professional scam artist, and will probably lose it all with no recourse. Natural instinct is to tell all your friends when you have a bad experience. In customer service it's well-known that every customer who has a bad experience tells at least 10 of their friends, vs. 5 or less for a good experience. In general, many people who get taken in a scam feel the need to warn others.
Ivars' child army of trolls - their foaming-at-the-mouth tactics to silence anyone who dares speak against Ivars, make some people even more determined to speak up, even if it's just to rub the trolls' noses in it. People have an instinctive need to be right, on both sides.
Re someone contacting you without your permission: I have yet to see any evidence of anyone being contacted directly against their will to warn them of Ivars' tricks - but I could be wrong. So far, all I've seen is posts on public pages like IGG, websites, Facebook pages, message boards. And nobody is forcing anyone to read any of those things, so it's not harassment. I deliberately avoid the IGG comments page, for example, because it's been a childish and pointless WWE style wrestling match for months.