If someone did that to me, I'm not sure I'd find it 'creepy'. Then again, I am fellow ENFP. I think it depends on how you do it, too. In general, I'm pretty blase about the wealth of free information on the 'net and I figure if you do NOT want people to find out X about you, then you would NOT have an accessible homepage etc. let alone tell people about it.
I think it helps on how you do it, too - like, "Wow, I couldn't help but notice on your homepage that you like fly fishing? So do I! Have you ever fished in blah blah blah place" When you use facts about people to help start conversations or show how you are similar, it seems more relevant and it shows you are interested in getting to know them better. I think, for me at least, that's natural and mirrors RL except IRL you usually find out info about people through them directly or mutual friends.
"Stalkerish" is when you start throwing out random facts like, 'You're O Negative and you went to 3rd grade at blah blah blah elementary school. I had a cheese sandwhich for lunch. Will you marry me?'
Ne curiousity and ENXP enthusiasm don't always translate well online. Actually, very rarely does anything translate well online until you get to know someone better.