Free: Contests & Raffles.
I am not against the use of trailcams. But I understand the logic behind restrictions in some areas. Logic. The most overlooked study in schools these days. Seems to be right up there with common sense and bigfoot in the rarity you actually see it. Just an observation. By their very nature trailcams are designed to monitor and "scout" without the user even being in the area. The majority of the other "technology advancements" mentioned in in this thread have not eliminated the need for an end user to be present. A long range rifle needs a shooter, high end optics, need an operator, gps, rangefinders, tech clothing, nice boots etc make it more comfortable, arguably more effective, but its requires a person be present. Trailcams CAN provide very important data that would often go unnoticed because the end user cannot constantly monitor X number of locations all the time. Trailcams can solve that.
I've got cameras that are not blackop, and the critters frequently alert to them at night. Can you imagine aa big buck coming in to 50 eyes in the dark at a watering hole?