All personal information I'll give to a stranger (and that includes the things that are on my user info) are my sex, age and the country I'm from. Apart from that, I don't share anything with anyone unless I'm somewhat comfortable. I never give anyone a last name until I'm completely sure I trust them, let alone an address. I try to keep anything that might give away my identity out of my public LJ posts - as soon as I write about something particular about where I live or what I do in daily life, it goes under a friend cut. It's not because I've got anything to hide; I'm just very careful.

I think you're more prone to get a stalker if you're interesting to them at first sight, and if they have a way of contacting you. Keeping any info that might lure them off your profile and public entries, and keeping your e-mail address and IM info safe seems like a good way to protect yourself.

You're right, no one should have to hide their identity. However, the harsh reality is that this world is fucked up, and there are many fucked up people in it. It's better to keep yourself safe than to trust people who possibly don't deserve your trust.