On September 9, 2018, I asked in /r/physics:

Which frequency ranges can copper attenuate?

/u/rrab and I have debated in /r/electromagnetics and /r/targetedenergyweapons the frequency range copper can attenuate. I submitted manufacturers' specifications and scientific papers which are archived in the copper wiki.

https://www.reddit.com/r/Electromagnetics/comments/73uewe/wiki_shielding_copper/

Based on my research, copper can attenuate microwaves but not extremely low frequency (ELF), millimeter, ultra wideband radar and ground penetrating radar.

/u/rrab believes copper can attenuate all of the above. /u/rrab refuses to cite sources and submit a shielding report.

Which frequencies can copper attenuate?

I asked the mods to approve my post. They did. Within 2 days, my post was removed. I asked why. The mods did not answer.