Hey there,
I found that since recently, 'sketchy' marked wallpapers start popping up in the results even though the filter is specified as SFW only.
This URI for example will show a query for which this is the case: [url]http://alpha.wallhaven.cc/search?categories=111&purity=100&sorting=favorites&order=desc&page=6[/url]
I think this is happening since a recent change, because they did not show up in the past.
Cheers,
Valradius