At the time it was not against NASA policy to carry along personal mementos. There was some wording about those being "sanctioned" by NASA, but the definition was pretty loose. The guys on Apollo 15 got into trouble with those postage stamps. Some were "sanctioned", others were not. The unsanctioned ones were planned to be kept by the crew and later sold to establish a trust fund for their kids' education. When NASA officials found out, they confiscated them all. Gus Grissom carried some Mercury dimes in Liberty Bell 7, which were recovered when the sunken craft was raised a few years ago. Buzz Aldrin took along a "communion kit" to the lunar surface, which caused a bit of a stir in some circles.
There are people now trying to raise the F-1 engines from some of the Saturn Vs that landed in the ocean during the launch of some of the missions. NASA put the word out that those are still considered "government property". The general guideline seems to be if it was manufactured for NASA and paid for by the public, it is still public (government) property. Personal items are still yours.
I don't know about the comments in the article's comment section that say something about Obama signing a law saying this or that about these items. Anything about Obama I would view with some skepticism.
“Anything about Obama I would view with some skepticism.”
Anything *good* about Obama I would view with extreme skepticism.