Hmm, I'm not as up to speed on the human brain, so I cannot speak for brain frequencies, however I am somewhat an RF communications expert. 5G uses multiple frequency bands from 600MHz all the way up to 60 GHz. The low band frequencies are in the common UHF spectrum and have been used for a very long time. That band is from 300MHz to 3GHz. The next higher band is 3GHz-30GHz, called SHF. The highest band we use for communication is EHF, 30GHz-300GHz. The only new band to be accessed is the upper SHF and lower EHF bands. We have been using both SHF and EHF for a long time for military satellite communications. The higher the band, the lower the power requirements, however obstruction is a serious problem for these higher bands. At one time, the EHF terminals couldn't operate in rainy conditions. Rain drops would capture the RF and it would literally just heat up some rain drops slightly. We would lose the satellite link every time it rained. The range becomes very limited in atmosphere, so the need to distribute towers everywhere because of loss of signal. High power RF is a significant concern at any band, the power levels involved here should not be a huge concern. Millimeter wavelengths tend to stimulate the top layers of skin, causing extreme discomfort, like your skin is on fire, but deeper penetration is extremely difficult for mm wavelengths. (Actually, the Army has a crowd control weapon that uses this particular effect to disperse crowds.) I'll update with a link to this weapon. This actually requires a very concentrated beam to have this effect, or a very high power amplifier. I can't seem to correlate any of 5G with mind control, nanobot activation, etc. Im afraid that is sci-fi stuff without any real backing in reality. I am extremely familiar with SHF, but only passably familiar with EHF. I worked on SHF terminals and dishes for years. EHF was not on my tasking at that time. Update link for crowd dispersal weapon. https://www.rt.com/news/weapon-us-microwave-cannon-363/