In late March, the Distilled blog reported Google began to block the "scam" related auto-completions within Google Instant.
I tried a bunch of examples, and although I felt I was seeing less auto-completions within Google Instant for the query plus the word scam, I still saw many cases of Google offering scam as a completion.
But the news was getting a lot of buzz around the SEO industry so I decided to ask Google about it. What did I learn? Nothing, after a couple requests, Google did not reply to me. Let me be fair, Google normally replies to me but for this request, I received nothing. Let me be even fairer to Google and say they later on worked with Danny Sullivan on his article named How Google Instant's Autocomplete Suggestions Work.
In Danny's piece, he commented specifically about the 'scam' words and said:
There are signs that Google has been pulling back by suggesting “scam” along with company names, but despite these reports, you can still find examples where this still happens. Google hasn’t commented if it’s actually made any change like this, by the way.
So now I am seeing people reporting the scam completions are back! Were they ever completely gone? Not from what I have seen, but people are saying they are back. If they are, I really believe they have been dumbed down a lot so that they don't show up as often.
Also make sure to read our Crafting Google Instant Search Suggestions story.
Forum discussion at WebmasterWorld and Google Web Search Help.