# Can I tell if a CD has been copied onto a computer? **URL:** \ **Category:** Factual Questions\ **Created:** [February 7, 2006, 2:00pm UTC](https://boards.straightdope.com/t/can-i-tell-if-a-cd-has-been-copied-onto-a-computer/343382 "2006-02-07T14:00:34Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Wallenstein](https://avatars.discourse-cdn.com/v4/letter/w/b5a626/32.png) [@Wallenstein](https://boards.straightdope.com/u/Wallenstein)\ **Post date:** [February 7, 2006, 2:00pm UTC](https://boards.straightdope.com/t/can-i-tell-if-a-cd-has-been-copied-onto-a-computer/343382/1 "2006-02-07T14:00:34Z")
A colleague at work told me that her son refuses to let people copy his CDs because, in his words, “it leaves a band around the outside of the disc, and you can tell it’s been copied”. Does this sound likely? I can’t work out how the act of ripping a CD would cause any physical changes to the CD itself - these are original shop-bought CDs, btw. Would it perhaps occur if the CD is ripped in a CD/RW drive, rather than read-only? This has vexed me mightly, for I can see no way it can happen. 😕 Any enlightenment appreciated! – e-logic Cambridge, UK ---
**Author:** ![SmackFu](https://avatars.discourse-cdn.com/v4/letter/s/53a042/32.png) [@SmackFu](https://boards.straightdope.com/u/SmackFu)\ **Post date:** [February 7, 2006, 2:07pm UTC](https://boards.straightdope.com/t/can-i-tell-if-a-cd-has-been-copied-onto-a-computer/343382/2 "2006-02-07T14:07:36Z")
No, copying a CD has no effect on the CD whatsoever. ---
**Author:** ![Shagnasty](https://avatars.discourse-cdn.com/v4/letter/s/9dc877/32.png) [@Shagnasty](https://boards.straightdope.com/u/Shagnasty)\ **Post date:** [February 7, 2006, 2:08pm UTC](https://boards.straightdope.com/t/can-i-tell-if-a-cd-has-been-copied-onto-a-computer/343382/3 "2006-02-07T14:08:19Z")
There isn’t much in-depth enlightenment to give. It simply isn’t true. Like you said, how would that work with a non-writeable drive? Normal store bought CD’s aren’t writeable at all. The CD drive only needs to read them to copy files to the hard drive. Very strange belief on their part. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [February 7, 2006, 2:20pm UTC](https://boards.straightdope.com/t/can-i-tell-if-a-cd-has-been-copied-onto-a-computer/343382/4 "2006-02-07T14:20:06Z")
He might be talking about copy-protected discs (which are not Compact Disc standards-compliant) - some of these work by the inclusion of an additional, unreadable (i.e deliberately corrupt) track that is ignored by domestic CD players, but that confuses computer CD drives and renders the whole disc unreadable. I have heard of people circumventing this method by obscuring the last track (which will be at or towards the outside) with a magic marker. It’s a bad idea, IMO - much better just not to buy from companies that don’t press standards-compliant media. ---
**Author:** ![don\_t\_ask](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@don\_t\_ask](https://boards.straightdope.com/u/don_t_ask)\ **Post date:** [February 7, 2006, 2:21pm UTC](https://boards.straightdope.com/t/can-i-tell-if-a-cd-has-been-copied-onto-a-computer/343382/5 "2006-02-07T14:21:45Z")
no ---
**Author:** ![Wallenstein](https://avatars.discourse-cdn.com/v4/letter/w/b5a626/32.png) [@Wallenstein](https://boards.straightdope.com/u/Wallenstein)\ **Post date:** [February 7, 2006, 2:55pm UTC](https://boards.straightdope.com/t/can-i-tell-if-a-cd-has-been-copied-onto-a-computer/343382/6 "2006-02-07T14:55:42Z")
cheers dudes - I figured that was the case 😉 ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [February 7, 2006, 2:58pm UTC](https://boards.straightdope.com/t/can-i-tell-if-a-cd-has-been-copied-onto-a-computer/343382/7 "2006-02-07T14:58:44Z")
Do ask him if he means what I described. Another alternative is that he says that because _he just doesn’t want to promote intellectual property theft_ and doesn’t particularly care to debate his reasons. ---
**Author:** ![handsomeharry](https://avatars.discourse-cdn.com/v4/letter/h/e9c0ed/32.png) [@handsomeharry](https://boards.straightdope.com/u/handsomeharry)\ **Post date:** [February 7, 2006, 3:05pm UTC](https://boards.straightdope.com/t/can-i-tell-if-a-cd-has-been-copied-onto-a-computer/343382/8 "2006-02-07T15:05:21Z")
> [@Mangetout](#): > > Do ask him if he means what I described. > > Another alternative is that he says that because _he just doesn’t want to promote intellectual property theft_ and doesn’t particularly care to debate his reasons. Or, perhaps he just doesn’t like lending his things and comes up with an obvious lie in hopes of you catching on and letting the matter drop. hh ---
**Author:** ![Tastes\_of\_Chocolate](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tastes_of_chocolate/32/3232_2.png) [@Tastes\_of\_Chocolate](https://boards.straightdope.com/u/Tastes_of_Chocolate)\ **Post date:** [February 7, 2006, 6:45pm UTC](https://boards.straightdope.com/t/can-i-tell-if-a-cd-has-been-copied-onto-a-computer/343382/9 "2006-02-07T18:45:11Z")
If he thinks he is seeing a band around the outside of his CD, I’d guess what he is really seeing is the unused part of the CD. CD’s are recorded from the center out. Any unused space can be seen as a shinier, slightly darker band around the outside. I’m often surprised by how much of a CD isn’t used by some artists. I want my 74 minutes of music, darn it. ---
**Author:** ![gotpasswords](https://avatars.discourse-cdn.com/v4/letter/g/c57346/32.png) [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)\ **Post date:** [February 7, 2006, 10:54pm UTC](https://boards.straightdope.com/t/can-i-tell-if-a-cd-has-been-copied-onto-a-computer/343382/10 "2006-02-07T22:54:07Z")
You’re all missing the obvious other half of the answer - look on the hard drive for the contents of the CD in question. Otherwise, it’d take an optical drive with a serious mechanical problem to scuff or otherwise mark a CD while that CD is being read. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [February 7, 2006, 11:06pm UTC](https://boards.straightdope.com/t/can-i-tell-if-a-cd-has-been-copied-onto-a-computer/343382/11 "2006-02-07T23:06:29Z")
Actually, I wonder if he might even have been talking about _how to identify copies_.