- Lost and stolen devices
- Data leakage
- Unauthorized access to corporate resources
- Spread of malware infections from mobile devices to the company network
The infographic has more detail:

Source:
http://www-935.ibm.com/services/us/igs/secure-mobility-infographic.html
Source:
http://www-935.ibm.com/services/us/igs/secure-mobility-infographic.html