No, that isn't true at all.
I have worked with many sites running vbulletin. It asks you for a customer number to verify the software you are using.

Once you provide them with a valid number, (or the number associated with that specific vbulletin sofware piece) you should be able to continue your setup. Make sure you have made the user and (I'm assuming you are using sql db) and sql db, and set up the config.php file with the correct information. After you are done with the setup, make sure you take out the install.php file in the includes folder. If you need any further assistance, feel free to slip me a private message. Do be warned though, If you are trying to create a gaming forum yourself, just STOP right there. Forget about the idea. It will fail just like the hundreds of rip-offs of nextgenupdate. The truth is, you will never have a forum as giant as nextgenupdate. Even if you want to have a decent forum it will run your bank dry. It takes a ridiculous amount of time and effort to have a "decent" size one. (20k maybe)

I have seen so many rip-offs of nextgenupdate that it makes me ask a question to the owners of those knock-off sites... Why even try?
So think about what you are doing before you commit to it because I wasted much time with helping people set up their knock off NGU's(*cough*Biz's site*cough*)