Striping only puts part of the data on each spindle. However, apparently each "block" can have multiple consecutive sectors so if you want no chance of outsiders reading the data you may be in trouble.

See [link|http://www.acsdata.com/raid-5-data-recovery.htm|ACS Data Recovery] and [link|http://en.wikipedia.org/wiki/Standard_RAID_levels#RAID_5|Wikipedia RAID 5].

To be absolutely sure that data can't be extracted from a drive you probably want to put the drive in a [link|http://www.magnetechcorp.com/Hard_drive_eraser.htm|hard drive eraser] or the like.

HTH a bit.

Cheers,
Scott.