Volunteers....help or hurt

Ministry includes many people which most are volunteers.   What is a volunteer?  Webster says "one who renders a service or takes part in a transaction while having no legal concern or interest"   We have to have volunteers to help us as we minister to our community. What are those things that volunteers can slip into that cause us all more harm than good?  Here are just a few
1. When they come unprepared
2. When they have a sense of entitlement
3. When they are subversive and sow discontent
4. When they complain often
5. When they think 50% attendance is highly committed