In the U.S. of A. we call PLC "BPL" for "broadband over power line".
Late 2006 the Federal Communications Commission stated that BPL does not interfere with radio communications. Then they created a new rule that says that when BPL interferes with HF communications
that licensed radio communications are FORBIDDEN to file complaints about the interference if the victim of interference is a mobile station no longer able to use the licensed service. This applies to ANY FCC licensed communications, whether aeronautical, marine, commercial, short-wave broadcast, weather facsimile transmissions, time and frequency standards etc etc.
A little information on the legal action against the F.C.C. for its alleged illegal ruling on BPL; https://www.arrl.org/forms/fdefense/
An ARRL article about the FCC stupidity; http://www.arrl.org/news/stories/2007/02/01/100/?nc=1
In the U.S.A. the best collection of information is at the ARRL.org site.
This page is a repository of BPL relevant information in the U.S.A. kept by W1RFI at ARRL headquartershttp://p1k.arrl.org/~ehare/bpl/ex2.html
This is the database that the FCC required to be made public so that we would have advanced notice of the interference;http://www.bpldatabase.org/
All BPL in the U.S.A. sorted by zipcode (so you do not have to type in code after code after code)http://www.bpldatabase.org/listing/
A electric power company in Indiana posts information about their attempts at BPL.http://www.sciremc.com/HighSpeedInterne ... fault.aspx
W1RFI visits the now-shut-down bpl trial near Miami and verifies measurements made by WB9JTK. See photos of BPL equipment;http://www.pbase.com/drennon/bpl
BPL in Manassas, Virginia, USA. One of the worst spectrum polluters;http://www.k4gvt.com/bpl/
This site has audio recordings of some BPL
A collection of RFI recordings to help you identify what might be the source of HF RFI; http://www.arrl.org/tis/info/HTML/rfi-noise/