From: Tony Sidaway:
You might think so, but it isn't. Even the most vandalized articles on Wikipedia are well under control. The category "Protected against vandalism", which contains a list of all pages currently with a vprotect template, is almost empty of real articles.
It's easy to get the Chicken Licken attitude if you don't look at the actual facts.
Vandalism is in no way, shape or form a serious ongoing threat to Wikipedia.
Thats because we only protect pages under fairly extreme circumstances. The real vandalism problem is the one we don't see, the articles that aren't being watched closely (i.e. the ones that make up the bulk of the ~750,000 articles we have).
The most vandalised pages are ok because lots of people watch them, only just a few minutes ago I reverted some serious one-off vandalism on a fairly important article that was done over 2 weeks ago. But even high profile articles are not immune to vandalism, if you monitor the Bill Gates article it is painfully obvious why it was so badly criticised; because it is a constant war between vandalism/crap editing and reverting back, any good editing just get eroded away.
The other problem that vandalism causes is that it wastes so much time of editors who would otherwise being making articles better rather than stopping them being destroyed. Plus, as I said, vandalism deters good editors from taking us seriously and contributing.
The real cost is the one you don't see. Not the one you see in recent changes.
Martin