I think the idea is to get those people who search for related to what is discussed on Bitcointalk through google. They would then be tricked to click on mirror links of threads similar to those on bitcointalk after which they will be prompted to log in onto the phishing website.
I think this looks well like a very smart and calculative move, I always try to use the forum's search engine and not google, though sometimes it's not really a straightforward process in searching for what you're looking for.
I thought if probably you're searching for a thread on Google, you'll just be redirected or taken straight to the thread? Does the user need to login there?