How to know if someone has blocked you on facebook ?

Step 1: According to official facebook announcement

"People you have blocked will not be able to interact with you on Facebook. Any Facebook friendships or relationships you currently have with that person will be broken. Note that blocking someone may not prevent all communications and interactions in applications, and does not extend to elsewhere on the Internet."

So it clears that if someone has blocked you on facebook then people may not able to communicate or interact with facebook. So if any person suddenly stops any communication with you then you can assume that he/she may have blocked you. But this method works only if you already a friend of him or his otherwise it won’t work.
Ok, the point above suggests how to know if someone has blocked you on facebook, but what if he/she is not already a friend of yours ? There are some other steps are there to know if he/she blocked you.
Step 2: Try search a person on Google.com search engine with his name followed by facebook without  quotation mark ex: “Richard Facebook” . If search engine indexes his profile then he/she may comes in search result click on the result without log-in to you’re current account on facebook and see whether he/she is active on facebook or not if he/she is active then you may be blocked.
Step 3: Try to ask mutual friend whether he/she is active or online for a weeks together. If the reply is yes then you’re sure blocked with the specific person who are not able to see online for a weeks together suddenly.
Step 4: Another method is creating a new facebook account and searching for his profile if he/she comes in the search result, send a friend request to them if they approve your request this show he/she is active in facebook but not for your account.
I think this are the only possible methods that can be used to find a blocked person in facebook. If you come across new tricks, do share it with your comments.