I want to consider a classification of vandalism.
Orthodox vandalism (ortho-vandalism) is the simple insertion of meaningless or false information, and/or deletion of correct information. I pass over mere damage and on to the insertion of false data. This can range from simple alteration of dates, names, links and so on. More interesting is the construction of material which is plausible but can be seen to be false, especially to those who think about the material: for example, donating several square miles of land in the City of London for public parks (hint: the City is often called "The Square Mile"). Special commendation for the construction of networks of articles, for example on bogus noble families, as works of art. I quite like the "Zelig" school of fiction: bogus characters who were also present at famous events. Since almost all editors never acquired the habit of reading books, alleged sources not in Google books are used to cover a multitude of sins.
Under ortho-vandalism I include crypto-vandalism. Acrostics (initial letters of words or lines), anagrams etc are vulnerable to normal edits. Since the edit record is harder to change, it is possible to leave concealed or cryptic messages in an article history or editors contribution histories. Anagrammatic user names are also seen.
Meta-vandalism is the manipulation of the community into the destruction of true information. There are articles which are so surprising that it is easy for the casual observer to believe that they must be hoaxes. For example, there is a real Lord Melchett, in spite of being better known as a character in Blackadder II. Creative use of the wrong link is also seen as helpful here.
Under meta-vandalism I place the contributions of sock-puppets (at least, those intended to be discovered). All of their contributions will have to be checked, and the task is made harder if they look like vandalism but aren't.
Para-vandalism is the manipulation of the community into the destruction of itself by falsely labelling true contributors as vandals and vice versa. The first stage is "intoxication" to confuse the distinction between the good and bad guys. Hoax articles are defended, true articles are decried by an army of sock-puppet, stooges and "useful idiots". Other hoaxers can usually be relied on to pick up what's going on and pile in on the right - or rather, wrong - side. The second stage is to turn the community in on itself by use of off-wiki sites to promote false claims and memes: claims that honest admins are corrupt; claims that useful editors are vandals and hoaxers; and vice versa. In the final stage the community completes its own self-destruction without further assistance, banning useful editors and blindly deleting their content, unthinking reversions, and an utter absorption in process and drama to the complete exclusion of content.