If I run a magnet over my ID card will it remove any information that cops can use?

I was stopped by the cops not too long ago. They took my ID did something funky with it and gave it back. A professor of mine told me if we ever got in a altercation with a cop to swipe a magnet against the black magnetic strip? Is this true?

No. The police would manually input your name into the system to get your information. The magnetic strip simply makes things a little faster. Also, the professor is a bit of an idiot for encouraging your to wipe your card. Not a good idea at all.