[baud147258]

well, checking the source can be complicated, if it's a web page that had disappeared before being archived or a book/publication.

[kristopolous]

The link rot on wikipedia is pretty bad.

I don't really have an easy solution. People aren't doing it in bad faith. Do laws prevent archiving for the purpose of referencing? IANAL but it certainly sounds like one of the copyright exemptions.

If so there could be a "wikisource" that fetches sites when referenced and then archives them. This isn't IA, it's a different goal really.