When should I detect TOC manually in EAC?

All the audio discs I have are copy protected but never got any trouble ripping them. but the track lenghts will always change some if I detect TOC manually.
Should I always do that, or when?

When you say that all of your albums are copy protected, did you determine this by looking at the 'Copy Protection' column in Exact Audio Copy? Every album I have ripped using EAC gives a 'yes' in that column, and some of them are from the 80s (before CD copy protection was even implemented). I am guessing it simply means that the album is under copyright.

If the extracted files sound ok and it rips without errors in secure mode, the album is probably not copy protected and detecting TOC manually is not necessary.

EDIT: Removed misinformation.

I think the "Copy Protection" is a flag that has always been standard in the audio-CD format, and the flag would be set to true for most copyrighted CD's to prevent standalone copiers from being able to copy the disc.

This is completely wrong. This flag doesn't prevent the possibility of pressed audio CD to be copied in the stand-alone copier but prevents the possibility of the copy to be copied again digitally

EDIT: Of course, you can't make a copy from copy-protected audio CD in the stand-alone copier; their flags are set so up that the device "thinks" it is copy already...

Why would a standalone copier let you copy a CD, but not a copy of a copy? Is it meant as a piracy deterrent? If so, couldn't you still pirate by just making as many copies as you want directly from the original?

Yes, that is right, but the copies will not spread around as fast (people who have one of your copies cannot make other copies)

More information about SCMS: http://www.xs4all.nl/~jacg/dcc-faq/scms.html