If that were the case, it would be the makers of the R4DS who would be in trouble.   I haven't seen the video since it came out, does it show the device being plugged into a DS? Does it show the DS doing something that it could not do without the R4DS? If this is the case, ESA could be saying that the video promotes piracy. But then again, they haven't said anything so who would know what they were thinking, or what they told YT.   I think it's just another case of the rich oppressing the rest of us - because they can. If you want to take it to court, even if you are in the right, they will bankrupt you with expensive lawyer's fees. Such is the way of the American legal system.