Since that article was published, things have changed a little bit. At least for the filtering use case they talked about in the blog, XDP (https://www.iovisor.

Since that article was published, things have changed a little bit. At least for the filtering use case they talked about in the blog, XDP (https://www.iovisor.org/technology/xdp https://www.iovisor.org/technology/xdp) has come about, which is an in-kernel mechanism by which to filter at wire speed. I don't disagree that there are many examples, but it's hard to solve them unless people give specifics.