Does the web site have any idea how rude it is to claim that my last name contains invalid characters? Clearly not. What they actually meant is: our web site will not accept that hyphen in your last name. But do they say that? No, of course not. They decide to shove in my face the claim that there's something wrong with my name.
There's nothing wrong with my name, just as there's nothing wrong with someone whose first name is Jean-Marie, or someone whose last name is O'Reilly.
What is wrong is that way this is being handled. If the system can't cope with non-letters and spaces it needs to say that. How about the following error message:
Our system is unable to process last names that contain non-letters, please replace them with spaces.
Don't blame me for having a last name that your system doesn't like, whose fault is that? Saying "Your last name contains invalid characters" is plain offensive. And I'm quite used to the situation that computer systems don't like the hyphen. On every flight I've ever been on I've been JOHN GRAHAMCUMMING.
The first time this happened the woman at the check-in counter did not say (in a robotic voice): "Your last name contains invalid characters", she actually said "I'm sorry, our system can't accept the hyphen". Fair enough.
So, form designers: stop blaming the user for your inadequacies.
PS Would accepting the hyphen actually destroy your database?
AOL sort of gets this right, although it claims it'll accepts numbers in a last name which, in fact, it won't:
Yahoo oddly believes that I don't know how to type my own name and decides to lowercase the C in Cumming. It's willing to accept the hyphen but not that I know who I am.
PPS Think of it this way; if I'm entering my name I'm probably signing up for your service. Do you really want part of my sign-up experience to be that you tell me that my name is invalid?