The 'wiki' principle relies on people improving previous answer, and this often involves removing nonsense as well as adding further material. Here are some examples of what can happen when the principle doesn't operate:

http://www.faqfarm.com/wiki.phtml?title=What_year_did_World_War_2_officially_end&action=edit

http://www.faqfarm.com/Q/How_was_the_British_economy_during_World_War_2

Here are two more examples:

http://www.faqfarm.com/Q/How_much_money_did_Germany_owe_the_US_after_the_war_was_over


http://www.faqfarm.com/Q/Were_there_any_...nghold_of_sorts

I may add a few more examples from time to time.

Yikes!

Question : "How was the British economy during World War 2?"

Answer: "...Great Britain was still a little shakey from the Revolution and damage was still evident..."

Oh, dear, dear....

Sometimes the Wiki principle fails to work. Here it seems to me - on this site where people answer questions asked by others, the real problem isn't vandalism, but lack of it! Anything that says that WWII ended ('officially', it should be noted) on March 31, 1942 and doesn't get corrected very quickly indeed is beyond the pale. The place is also a bit like Speakers' Corner (in Hyde Park) with far too many people, including some editors, on soapboxes.