You presume users understand what the difference is. Not all users are technical enough for that sort of thing.

Someone also points out a related problem: if the user complains on social media instead of directly to me. I don't always have the opportunity to explain at all.

> Perhaps that was a good thing, because it made you aware of its presence quickly.

Unfortunately, being aware of its presence didn't help much. I considered alerting the user that they had malware, but generally the only time a website tells a user they have malware is to scam a user (see: MacKeeper), and I didn't want users to see my site as untrustworthy.