Haukur Þorgeirsson wrote:
If plagiarism does NOT qualify as copyright infringement, then it falls foul of WP:CITE. Citing one's sources is not an option on Wikipedia; it is policy.
Last time I clicked on "random article" ten times in a row I did not get a single one which cited references. Citing one's sources may be policy but it is not strictly enforced policy.
It's a relatively recent policy. Since it wasn't always so it just means that many articles written before that don't have references.
Ec