Vlad something to consider is not everyone wants to register and people are quite comfortable lurking and/or reading a forum. I think the option should be left up to the individual. For instance, when I go to a bookstore or a public library, I would not want to register at the desk to let them know I'm just browsing nor do I want to interact with the patrons.
This reminds me of the NSA and tracking people's communications via email or phones conversations. It's a little too much like
Big Brother for a lot of people. Freedom of choice is important in cyberspace too after all it's an avid reader's dream come true. Please don't close the door on potential visitors who might enjoy your forum without wanting to register.
What is the 1 percent rule? (An article addressing this issue)
Technology | What is the 1% rule?