When I'm stumped for a planet name or an organization name or something, I usually search on Google for a free name generator. But are the names in random generators copyrighted? If I used a generated name in a published work, would I have to credit the generator? Is using a generator even a good idea, or could I somehow get slammed for plagiarism?
As far is legal rights are concerned, no, names generated by a generator are not copyrighted, nothing similar. Consider: a random string generator producing random letter combinations of random lengths could theoretically produce every word in the dictionary. One cannot copyright those, right?
A name generator is only a little more complex than manually flipping open a dictionary at a random page and pointing your finger at a random word. Would you have to credit the dictionary, if you used it this way? Is taking words from a dictionary "plagiarism"?
(Whether using an online name generator is a good idea from a creative point of view is a different question entirely, and a separate one.)
I find them helpful, but often wrong.
I used one that has different ethnic groups to get ideas for names. Always always Google the name that comes up. Some of the "girl names" turned out to be used only for boys (sometimes it went the other way). Names said to be Egyptian turned out to be Hebrew. Names said to be Hebrew turned out to be Yiddish. In some cases, the names were of famous/known people (but not celebrities).
In zero cases (out of maybe 100 names I Googled from the generator) did I discover the name came from a specific copyrighted work.
As for credit, no, you do not need to credit it as a source. The generator either spits back names loaded into it with particular tags or it creates names based on certain algorithms. The programmer does not own the names.
You can not copyright a name. Don't use well-known names that are unique but the legal issues for random names aren't something to worry about. Google is your friend though. Find out where the name comes from and proceed accordingly.
As Henry Taylor pointed out, using a random name generator does not protect you from copyright violations. But I think the thing you more need to worry about is if it violates a trademark. This might not seem like a big distinction, but they're two different types of IP, and they're enforced in different ways. I'm not a lawyer, so all I can say is you may want to look into whatever names you use to see if they could be a problem. It's usually not a real concern, even in the litigious US, but in the rare cases when it can be, it can be quite a big deal. For example, don't name your mouse-like character after a certain very well-known mouse. But you probably already knew that one.
That said, using a random name generator generally won't open you up to more problems than just picking a name out of thin air, especially if you've spent too much time watching Disney's IP. Disney is, of course, a registered trademark of Disney.
Are randomly generated names copyrighted? ...maybe. A random algorithm can generate a sequence of alphabetic characters which spell out a copyrighted name. The fact that the name was randomly generated neither guarantees that it is not copyrighted, nor protects you from the consequences of violating that copyright or trademark.
Beyond those legal failings, random name generators also waste the incredible opportunity which naming provides an author. Names, like every other word which describes a character (or planet or corporation), should help the reader visualize and understand the entity it is attached too. Subtle meanings can be hidden in names which can give readers a clue as to how this might evolve. If your hero has a trusted assistant named Judas, your readers might be hesitant to share your hero's trust in that man. This can lead them to accurately predict or completely misread upcoming events in the story to very entertaining affect.
Don't waste your naming opportunities on a random throw of the dice. Pick up a thesaurus and let your creativity free.