Are there laws governing what parents can name their children?

[celtic owl]

For the most part, in the US, the naming of children falls under the purview of the right of free speech.
The only restrictions I'm aware of in this country is a ban on numerals and symbols.
That's why Chad Johnson, who wanted to change his surname to his jersey number (86) had to spell the name out in Spanish to get it approved (Ochocinco).
There have been a few attempts for names like THX 1138 (a movie reference) and # but the baby named # actually had to be called Hashtag.

The main reason for not allowing numerals or symbols lies in standard reporting indices (indexes).
SSA and IRS computers, along with most government agencies are not equipped to handle numbers and symbols in names.
In fact, federal computers don't even handle hyphens well so numerals and symbols are just not allowed.

On the flip side, there was a girl in Iceland who wanted to use the name given to her by her mother.
Mom named her Blaer (meaning "light breeze") but that isn't on the list of 1,853 approved female names in Iceland.
She was always called Stulka which is a generic term in Icelandic for "girl".
Recently, she won her court case and is being allowed to use her name.

There are times when I would agree with your feelings but the other side of the coin is a complete abrogation of our Constitutional rights and I find that more fearsome than a child with a weird name.
The child can legally change his/her name but, once our rights erode, it's nearly impossible to regain them.

So, I say we have pity for the poor children abused by idiot parents and do all we can to help them gain self esteem and to overcome the negatives posed by their names.