Agree with what Ranjith says.
Lock is a term I associate with reasons like spamming/flaming/trolling, etc and not with mission accomplished. If that is indeed the reason being cited, then I am against it.
Taking a hypothetical example here -
Suppose Manas Kumar Sahu is travelling when Ranjith answers his query and is unable to follow up on his query. On returning, he peeps in his thread, reads the reply and now wishes to post a further question there. But what does he see? "This thread is locked". He is clueless of what next is to be done and prefers leaving the place rather than banging his head and wasting any more time over the issue.
And if the same was one of my threads, I would want to return to it and find it open even if it simply meant me saying a thank you!
Having said all this, I would also like to add that if there is any other reason that bothers the IndiPolice and leads them to take the step, then a discussion in the open is always welcome. 
PS: No offense meant to anyone. 