There’s recent useful research into Bluetooth beacon security from The University of Hong Kong. The paper on Security and Privacy of Wireless Beacon Systems explains how widespread deployment of Bluetooth beacons can cause them to be an attractive target for adversaries.
The paper covers security issues and privacy concerns and classifies the possible types of attack.
The three main reasons for attacks are for free riding services, user profiling or service disruption.
Understanding adversary motives, capabilities and the potential impact allows for defence mechanisms and planning for remedial actions.