Direct Sequence Spread Spectrum (DSSS) is a popular modulation technique for wireless communication that reduces the probability of interference and enables sharing of spectrum. It is also the central technology for Low Probability of Detection (LPD) and Low Probability of Intercept (LPI) radio systems. In addition to being used in well known systems such as Wi-Fi, ZigBee, and GPS, DSSS is extremely popular for proprietary satellite communications and for terrestrial radio transmissions that people don’t want you to notice.I will show how DSSS signals can be detected much more easily than most people realize, and I will demonstrate techniques for reversing the pseudo-random sequence used in a DSSS implementation.