Well, on one hand, Yahoo! was hacked, exposing some 500M accounts. OTOH, DU folks' email addies were given to the DNC and/or CHILL campaign; Podesta fell for a phish, and probably rbrnmw fell for it, too. If anything happened at all.
BTW, though I've never used one and don't know how - or care to - proxy servers are used to conceal both the identity AND the location of the proxy user. IOW, it might be a Russian proxy, but it all but certainly was not a Russian user. A US user is vastly more likely.