Data secured with EFS, what about Previous Versions storage?

I have my data files stored in d:\data, which is encrypted with EFS. My removable drive backups are all encrypted as well. Obviously, I don't use MS Backup for that, since it has no encryption. I felt reasonably secure until I learned about the data file copies that are created with each System Restore Point. These are the ones restored with "Restore Previous Versions" on the Explorer drop down menu. They are stored in the Volume Information folder.

Could these files be read by someone who got hold of my internal hard drive? If so, is there a way to encrypt these files? I do realize that these "previous versions" files are limited. It is not my whole data folder, just most recent changes and limited by the size I set for previous versions storage. Nonetheless, I am wondering if I should just turn of this Windows feature for security.

Windows 7 Ultimate

Encrypted files that are saved by System Restore or Previous Versions retain the encryption placed upon the files.