I get this question ... alot.
Due to the different perceptions of the Church of Christ
1. The acappella fellowship and differences of:
a. Mutual Edification - oppose local preacher, and institutional support.
b. Oppose having separate Bible school classes
c. Non-institutions - against church support of such.
d. One Cup used for communion etc.
e. Being dogmatic on acappella music (If use instruments going to hell crowd)
2. The Boston Movement of the Church of Christ. (Cult-like in evangelism and small groups)
3. The variety of Churches of Christ in the Restoration Movement from the acappella fellowship to Christian Churches/ Churches of Christ (Independent) and the Disciples of Christ) (Not to mention the United Churches of Christ etc)
So what is the answer? The answer is the Boston Movement used to be classified as a cult. There are churches that can be cult-like .... and what you need to ask is:
1. Is the preacher focusing on himself or pointing people to check it out for themselves?
2. Are you to follow the leader or follow what the Bible teaches?
3. Who do they say Jesus is?
Others (within "Christianity") might classify "us" (Those in the Stone-Campbell movement/ Restoration Movement/ Christian Church/ Churches of Christ "Denomination") as a cult due to the differences we have theologically with them - especially in the issue of baptism. We believe it is part of the process in the plan of salvation. (We've even been called water regenerates) - others do not. Does this make us a cult? Nope ....
So is the Church of Christ a cult? I don't think so. My prayer is that the Church whether Church of Christ of Christian Church or what have you be the Bride that makes Christ proud of us. So let's go out and be the Church to the World.
(In a side note, I see our congregation very doctrinally conservative as the acappella fellowship ...with the goal of trying to be Jesus to the World)