I'm not sure that it's fully correct russian translation. In russian language correct term for "follow" is "следить" or "читать", but I choose term "подписаться" (correct translation for "подписаться" is "subscribe") because it sounds better in russian language.
Also translation's for "object_type_" choosed in assumption that "object_type_" strings would be used only in
%1$s %2$s %3$s
%1$s %2$s %3$s in reply to %4$s
messages. Because "Somebody create collection" translate in russian as "Кто-то создал коллеки_ю_", but "collection" translates as "коллекци_я_" (see to last char of word "коллекци_я_").
But despite this problems I use this translation.