If you're having a SharePoint 2010 webapplication which allows access to anonymous users, you may find that when users click on listitems, they get prompted to log in. This is the case for publishing sites where the ViewFormPagesLockdown feature is automatically activated and denies access to the list and its items. So for example when you're having a list with news items and you want users to be able to click on the item so they can read it, they will have to log on before they can see it.
Warning: Keep in mind that when you will disable the ViewFormPagesLockdown feature, it will have consequences. One of them being that the /_layouts/viewlsts.aspx page showing
all lists in the site will become available for anonymous users as well. This means that
all your lists will be accessible by default unless you specifically define permission inherritance to be broken on each list and specify anonymous users to not have access. Some lists may not be blocked this way, for example your pages library. This means that anonymous users will be able to see
allpages that exist in the library. So consider building a custom webpart to disclose information from lists to anonymous users above disabling this feature.
In order to prevent this from happening, follow these steps: