In regards to this question, I am not sure but I feel the answer requires a 'hack' of some sort. At least something that would violate a ToS. That fact that nobody has answered it makes me think it is not something easily done or intended and would cause a violation.
In handling questions like this, is it best to vote to close with reasoning as a comment?
I don't know enough about MW2 to know the answer to the question, but let's assume the answer is a "hack." A valid answer would then be:
It is impossible to do so from with in the game because (INSERT REASON HERE). However, it is likely that what you encountered were people using third party utilities. Such utilities are not permitted based on the ToS:
(INSERT QUOTE HERE)You may report anyone you see doing so to (INSERT LINK HERE)
We tangentially covered this over in this other question, but I feel we can be clearer with regards to this in its own question right here.
Closing should be judged on the question, not its answers. A question about a clearly illegal activity is unacceptable. But a question asking about an activity that has been spotted whose answer is that such an activity is illegal, that's all that needs to be said. The same goes for questions like certain plot and character questions. Sometimes the answer is simply "There is no clear canonical interpretation".
If you can only find seedy solutions, don't post them. If you can't find non-seedy solutions, then suggest that there might not be any such solution. "There is no solution that we can provide" is a perfectly valid answer that we can provide without needing to close this kind of question. You can pick either a comment to keep the question floating attractively, or an answer to propose a conclusion to the question. In either case, you are free to delete your post/comment if it turns out that you are wrong.
Now, if despite all this, the question does devolve into discussing seedy activity or subjective interpretations of story, then definitely we should close it.
