Allegations about the Crossrider Application include reports that search preferences are altered and signatures may be appended to email in certain situations. There is a lot of wisdom in not being an early adopter of programs that interact with social networking sites.
For Facebook, the only safe thing to do is to totally disable applications as Facebook has a history of utilizing the technology to share information without your knowledge or consent and most Facebook applications cause Facebook to switch from Https to http, potentially exposing your data to others.
Director of Technical Education
Cyber Threat Analysis Center
ESET North America
Author ESET Research, We Live Security