Does the password on OSX user account prevent someone from viewing your /user folder if they have the HD in an external enclosure?
Unless you have turned FileVault on which encrypts your drive your files can be read by anyone who has physical access to your machine. They don't need to take the disk out and put it into an external enclosure, they can boot into single user mode which can read every thing or boot into the recovery partition and either reinstall the OS without deleting data or I think add admin users or boot of a Linux USB drive.

If you need to protect your data you must encrypt it and the Apple way is top use FileVault and then you need a password to read the drive.