With the aim of manufacturing faster devices, the electronic industry scales down device's dimensions and is today entering into a nanoscale and Terahertz frequency regimes. In this work, we show how the reduction of the length L of the active region of two terminal devices implies (apart from the expected improvement of their dynamic behavior) a typically disregarded increment on the fluctuations of the current. In particular, the high-frequency current fluctuations are proportional to 1/L so that the noise grows unlimitedly when the device's dimensions are reduced. This important drawback, common to classical and quantum regimes, remains mainly unnoticed by the scientific community. © 2013 IEEE.