This is just getting on my bloody nerves now.
I just constructed a helpful, (albeit slightly lengthy) post to put on a particular thread (on AIBU,) and I took about 20 minutes to construct the post, and did the 'preview post' thing to check for typos, and the thread had been deleted! It was only put up there at 12.05pm!
Whether the OP didn't like the responses she got I don't know, but this is genuinely pissing me off now, and is making me feel like I can't be arsed to bother posting any response, unless it just takes a minute or two to type out!
If I have a ream of helpful advice and information, why should I bother typing it all out, when there's a risk that the OP will tell mumsnet to delete the thread, before I can submit my post?!
Why does this keep happening ?!!! 
Why bother posting a thread on here - and they are often lengthy original posts - just to tell mumsnet to delete it an hour after you posted it! And it's always 'privacy concerns!' 
Even the posters who managed to actually post their response before the thread was deleted have wasted their time.
As I say, at this rate, people are just not going to bother posting anything that takes longer than a minute to type out! Why bother, when there's a risk that the thread may go 'poooof' anyway! 