Anyone tricked by such a scam instantly becomes more cautious and discerning as do their friends and family. They become less likely to click on links in email or tweets, less likely to visit unfamiliar websites, to open attachments, or to download almost anything.
At the same time, I believe people become more likely to limit their virtual travels to websites they already know and trust. That's good for established brands. I also think that when confronted with new information those same consumers are more likely to check with a friend before buying or even clicking. This check-with-a-friend behavior could really drive word-of-mouth.
My wife fell victim to the Twitter scam over the weekend. We discovered the problem quickly and she reset all of her passwords. Not surprisingly, when I received an email from my sister today with a video attachment called "Christmas Dinner" and body text that said only "This is fun!" rather than clicking, I called her to confirm she sent it and wound up talking for several minutes.
If my behavior is typical, then people may call friends to get their opinion before engaging with brands they discover online. "What do you know about______", they might say, and the word-of-mouth event continues from there.
I'm sorry to say that I expect spam, scams, and phishing from unscrupulous people to increase. Fortunately, we have word-of-mouth to protect us. Spread the fire. GS