I'll get to the point- Is it legit?
No. Doesn't Work. After my very test, I have concluded that the MSN fanatic does not work and may be a scam. It may harvest email address or send spam to you. I will be observing whether the email that I have never disclosed to anyone (recently made it for the test) get a large amount of spam. (By the way, for anyones informations, it is not a email address that is a spammer could just think up of, so it is very conclusive that if spam is directed at this email address, it is the result of giving it to MSN fanatic block checker)
I have heard a lot about MSN block checkers (web apps or programs that can check whether you have been blocked in a message), but not from very trustable sources. People that I am sure that I don't know often advertise these sites and often get blocked immediately by me. Ironical?
The first results for "MSN block checker" on Google gives a MSN fanatic block checker. (not going to add the link, just check it up in google if you want to see the website for yourself.) I have checked up on the site but have not been able to get a definite answer on whether the site is legitimate. Is it a scam? McAfee Site Advisor gave the all clear for being safe, but there have been user reports of popups and spyware. Keep in mind that MSN fanatic block checker could be a scam to steal your password or to collect up email address to sell to a spammer. So I took the neccessary precautions before testing the site myself. Apparently it is also possible to DIY with a msg api (don't know what it is, can someone fill us in).
It was a simple test. I made 2 hotmail accounts. I added each other and had on block the other. Using MSN fanatic block checker, I tested whether msn fanatic could determine if that email has blocked them. (found out afterwards in the FAQS that I really didn't need to do this) MSN fanatic block checker supposedly told whether a contact was really online or not. So I was signed in on the blocked account when I used the block checker.
Doesn't work. I tried it several times. However, each time I enter the email address that I was signed into, it told me that I was not signed in. Msn Block Checker: Myth Busted.
Don't trust it.
On a side note- if it does work for you, please post a comment. I would be very interested.
Update (3/4/10)- Apparently back in the day, MSN block checkers work. However, there was a change in policy at Microsoft has changed their policy, leading to all MSN block checkers to stop working. However, if a user disables a certain setting (why would they?), then MSN block checkers can still check whether that contact has block you (quite unlikely).
This is from information retrieved from MSN Tools.NET. This is an excerpt (the important bits) from the guide:
Back in the day, due to the way Microsoft had configured the privacy settings for Passport and MSN Messenger accounts, a Block Checker could find out if a use was really offline or if they had blocked you, block checking was easy and common. Microsoft recently changed this privacy configuration so block checkers can no longer check you if a certain person has blocked you, unless the person has turned off this privacy feature, which is not very likely!
In case the person has not turned off the privacy feature (it's On by default), a blockchecker will most likely tell you that the contact (the blocker) is offline and has not blocked you on MSN Messenger, even if they have blocked you.