"A cloned chip could give criminals access to your health insurance or your medical files, said Kerr. A changed medical record could mean someone no longer qualifies for health insurance or put someone's health at risk. "For example if someone got into my health- care record they could take out the fact that I am deathly allergic to peanuts."
"Kerr's main concern with the VeriChip, however, is that no one seems quite sure who should be in charge of regulating it. While some hospitals in the U.S. have implanted the chips, some people in Canada seem to be looking at the device like an extreme form of body piercing.
""My concern, first of all, is whether or not the chip is even playing the role of a medical device," he said, comparing it again to a MedicAlert bracelet. "That bracelet might save somebody's life, but it's not a medical device. It's something which is an identifier that can be applied in a way that has a good medical outcome, but it's not like a scalpel."" 
"At the House hearing, state Rep. Ed Setzler (R-Kennesaw), who is shouldering the legislation in the House, spoke earnestly for better than a half hour on microchips as a literal invasion of privacy.
"He was followed by a hefty woman who described herself as a resident of DeKalb County. “I’m also one of the people in Georgia who has a microchip,” the woman said. Slowly, she began to lead the assembled lawmakers down a path they didn’t want to take.
"Microchips, the woman began, “infringe on issues that are fundamental to our very existence. Our rights to privacy, our rights to bodily integrity, the right to say no to foreign objects being put in our body.”" 
"Although the FDA approved the VeriChip implant last week, their approval does not mean the device is completely safe, according to an FDA letter CASPIAN has obtained. The letter, dated October 12, 2004, was sent to Digital Angel Corporation and outlines a number of potential health risks associated with the device.
"Among the potential problems the FDA identifies are: "adverse tissue reaction," "migration of the implanted transponder," "failure of implanted transponder," "electrical hazards" and "magnetic resonance imaging [MRI] incompatibilty." Not to mention the nasty needle stick from the "inserter" used to inject it. (The FDA lists "failure of inserter" -- a bloody possiblity we'd rather not contemplate -- among the risks.)" 
"The potential risks to health associated with the device are: adverse tissue reaction; migration of implanted transponder; compromised information
security; failure of implanted transponder; failure of inserter; failure of
electronic scanner; electromagnetic interference; electrical hazards;
magnetic resonance imaging incompatibility; and needle stick. The special
controls document aids in mitigating the risks by identifying performance
and safety testing, and appropriate labeling. Thus, in addition to the
general controls of the act, an Implantable Radiofrequency Transponder
System for Patient Identification and Health Information is subject to the
following special control: Class II Special Controls Guidance Document:
Implantable Radiofrequency Transponder System for Patient Identification and
Health Information."