before you reply witnessed pls check the message that you are quoting. that post doesnt have a message and its signature so he cant prove that he own that address..
pls put the current date in the message of the signature
I makes no sense to post the address of someone else as it would only allow said someone to regain control over your account. A signed message is also not needed IMHO as this will obviously not increase the credibility of the post, only time will. Lets say I gain access to an account this morning and posted an address a few minutes later. This address will hold less credit over an address that was posted last year.
When signing a message, one should allways include a date, yes.
IMHO MAsterV's message is very generic and might be misused.