If someone contacts you and you're not interested in them, giving the silent treatment is okay. It might seem rude in the 'real world', but in the world of online dating, it's common.

It's not okay to ask personal questions like 'Where do you stay?' and 'Which company do you work for?' before meeting someone in the 'real' world. However, after meeting, and provided both sides are okay with it, it's okay to provide personal information. You might want to hang on to your bank detail and credit card information, though!