Hey,
One common form of vandalism in Wikidata is removing sitelinks (we already have an abuse filter flagging them).
One of my friends in Persian Wikipedia (who is not a wikidata editor and only cares about Persian Wikipedia) asked me to write a tool that lists all Persian Wikipedia sitelink removals. So I wrote something small and fast but it's usable for any wiki. For example English Wikipedia: http://tools.wmflabs.org/dexbot/tools/deleted_sitelinks.php?wiki=enwiki

It's slow due to nature of the database query but once it responds, you might find good things to revert.

Since this is the most useful for Wikipedia editors who don't want to patrol Wikidata (in that case, this query is the most useful) I'm reaching to wider audiences. Sorry for spamming.

HTH
Best