The concern is about phishing via URL spoofing. For example, a user might see a URL like `google.com@mycoolphishingsite.se` and believe that "google.com" is the

The concern is about phishing via URL spoofing. For example, a user might see a URL like `google.com@mycoolphishingsite.se` and believe that "google.com" is the domain. The warning is intended to point out that "mycoolphishingsite.se" is the real domain.