Thou shalt not do this because surge/spike filters also happen to filter out frequencies relevant to powerline networking communications. Plain powerstrips also degrade signal quality, plus the open length of cable produces a lot of unwanted emissions in that frequency band.

There is a much better solution for when you are out of wall sockets: Use a powerline adapter that has a passthrough socket. That gives you powerline connection in the place where it belongs - directly on the wall - and these also contain filtering circuit.