Citat:
Data on persons may be stored for a maximum of 10 years and must result from a decision taken by the competent authorities in the Schengen State issuing the alert. Such a decision may arise in the case of a person who was subject to measures based on a violation of national regulations on the entry or residence of aliens or in the case of a person who committed a serious offence in the alerting State.
http://www.mediavisa.net/schengen-information-system.php
Sell 'crazy' some place else. We're all stocked up here.