Final answer:
Sociologists are concerned about cults affecting religious freedom by enforcing change through brainwashing and social pressures, which can lead to clashes with the law and significant life changes.
Step-by-step explanation:
Sociologists were concerned about the impact on religious freedom of cult members because cults were employing methods such as brainwashing to enforce a change in religious beliefs. Sociologists study these groups to understand their workings and implications on individual choice and freedom. The social pressures from cults or the mainstream society can significantly alter an individual's religious practices and infringe upon their religious freedom, often leading to dramatic changes in their life, or even clashes with the law, as seen in the case involving the 'Yearning for Zion' group in Texas.