He's referring to plain-old civil asset forfeiture.
Asset forfeiture has been controversial since it started being used much more frequently in the 1980s. I really doubt most of the people commenting on it here first heard of it on John Oliver's show.
Furthermore, the use of "plain-old" was a way of indicating that this is a new method but an old process; eg, it's not legally any different from normal asset seizure.
Finally, and most importantly, I don't see any bias or why you even call it that.
Not that there is anything wrong with John Oliver hopping on the band wagon, that's good thing.