In the November 16, 2005 New York Times ("Business Day" section), Tom Zeller, Jr. has a follow-up article to his piece discussed here. In this article, he reports on Sony BMG's decision to recall millions of CDs that have copy-restiction software on them. Except Mr. Zeller writes it as "CD's", just as he did in his November 14 article.
This time, he uses "CD's" at least 12 times. And he uses "PC's" twice as well.
Again, the proper way to indicate these plurals is CDs and PCs. But I'm beginning to think that this is house style at the Times. After all, the headline for Mr. Zeller's November 16 article is "CD's Recalled For Posing Harm to PC's".
It may be house style, but it's still sloppy.