Sometimes what happens is people post honest links to actual quilts, but some 'heathen' gets into the code and redirects you first to their porno website. This is not the original posters intent, and usually an honest person won't even know this has happened. It happens to businesses often. It's called 'high-jacking'.
Only the original poster can clean it up - or the business cleans it up. So if this happens when you go to a business link, know it's a high-jacking situation and the business will resolve it as soon as their aware of it (sometimes it shows ordinary advertisements as well as porno stuff). Give them some time and try back.
In addition, it may have been someone just posted that porno link - and created a user id to do so. In which case, I'm sure the moderator will take care of it when you notify them of the user id.
Hope this helps to explain what happens sometimes :)
Debbie in Austin