Which of the following is considered a common characteristic of terrorist groups?

Being highly mobile is indeed a characteristic often associated with terrorist groups. This mobility allows them to evade law enforcement efforts, relocate to different areas for operations, and adapt to changing environments or pressures. The ability to move quickly and effectively can enable terrorist groups to launch attacks unexpectedly, escape after an operation, or evade capture. Mobility can also assist in the logistics of planning and executing attacks, as well as facilitating the recruitment and training of members in diverse locations, which can further increase their operational capabilities.

While other characteristics, such as utilizing social media for recruitment, publicizing operations through press releases, and conducting open meetings with community members, may be observed in certain contexts, they are not universally applicable to all terrorist groups. These activities depend on specific group strategies, their target audience, or the nature of their operations, which vary widely among different terrorist organizations.