The forbidden message could refer to a link that is inside a site that requires user account. Back in the old days, you could access links to Universities, Government Agencies etc posted on the internet but nowadays, you need to go to the main page and then ask for permission from the webmaster or the account that the link is set, no longer exists.
Also, some of the older links used scripting that is no longer accepted by most browsers including Google Chrome, that could be the reason.
The .net suffix is not for general use, more for schools, universities, etc. .org is more inclined for organisations like charities.
Perhaps you could add one of the links you are trying to access?