Now that Ozzu has been around for a few years, there's going to be more instances where content linked to in members older posts is no longer available for whatever reason.
One example that can be rather scary, is when someone has an image in their post or signature that was linked to via an
HTTPS URL and they've allowed their
SSL certificate to expire or otherwise become invalid. When this happens you may see an alarming warning message displayed by your browser about invalid security certificates.
If you happen to come across threads (especially old ones) that cause your browser to warn you about security certificates being invalid for any reason at all, be sure to let a moderator know about it either by PM or using the Report Post icon in a post. Chances are it's simply a dead image which is no real cause for concern and a moderator will remove it.
