Do you have any proof of this? I haven't heard this before and they certainly have an active enough community to push things to the r/all quickly.
Another suspect thing is that time when the Reddit algorthm broke and the first 50 pages of r/all were turned into /r/the_donald post. Apparently what happened is that the sorting broke and they were ordering posts by activity, revealing that /r/the_donald posts were being upvoted at a rate that dwarfed other subreddits.
Disregard the title as it's not a "botnet." It's a user script that adds functionality to RES: automatically upvote everything in The_Donald, automatically downvote everything in other subreddits, and allows importing lists of specific users to up/downvote.