Wu Long entered the capital after paying a toll. He was heavily inspected on the way in and the guards looked at him with the same suspicion the troops outside did, but as he showed his disciple badge they let him through.
It was not like disciple badges could not be faked to show in front of mortals who did not have the means to check Spiritual Qi records within the badge, but doing so will make the perpetrator a mortal enemy of the sect whose disciple they impersonated. Cultivation sects universally supported each other's pursuit of such individuals since it was a good mutual assurance for all of them.
Thus impersonating a disciple of one sect will make one hunted by all sects in the region. Not many were willing to risk these repercussions. And certainly, not mountain bandits who generally had more or less fixed areas of activities, and therefore could be found and eradicated if all the sects in the region got serious.
