I believe that all regular users have the address bookmarked so that is not a problem and the other part should be handled with good SEO in my opinion. Simply don't give phishing sites opportunity to come on top of search results.
With so many Sinbad Phishing sites regular users should bookmark the real one, problems are those who got it from word of mouth and just typed in Sinbad, and ended up in phishing sites, phishing sites sometimes ended up on top of the results in search engine.
It's good that Sinbad had a campaign here, the campaign is for awareness of the real Sinbad it's what differentiates the real from the fake ones.
With so many phishing sites they need to keep up with the marketing campaign here for users to land on the real Sinbad, if people are in doubt about the real Sinbad they should just check these signatures posted here in this forum or the announcement thread.