This story didn't happen to me, so some of the details are going to be a bit dodgy but the person that it did happen to is someone that I have known for a long time and they stood to gain absolutely nothing by lying to me about this and therefore I believe them.
They were traveling on a budget night bus with a lot of other foreigners in Malaysia and at one point in time they told me what their destination was but I forgot. It isn't important to the overall story and this is mere just a bit of a warning to people that get on cheap overnight busses anywhere in the world, not just Malaysia.
I have traveled Malaysia extensively and found it to be incredibly safe, so please don't think that I am bashing this one country. I believe that there are dangers in traveling basically anywhere in the world but you need to be a little bit on the smart side to avoid it happening to you. Nobody could really see this coming and my friend in question was already applying quite a lot of caution but still got robbed.
While things may have changed since the day this happened, I can say from experience that there really isn't that much difference between the various buses that exist on these budget night trips. I do recommend the night buses because there is less traffic, maybe you can sleep, and you get to skip a night's accommodation at a low price. But you need to be careful with your belongings on these things.
It has long since been very well known that you better not store anything valuable in any bags that you stow under the buses, because the luggage handlers have access to them and since that area is out of sight, nothing much is stopping them from going through people's bags while they sit above probably sleeping. There is no way that you can monitor your bag because you, as a passenger, do not have access to these areas. The workers do (or at least did) though.
But that is not what happened here. My friend, realizing that this was potentially the case on any overnight bus in most places in the world, put all of her valuable and cash in a bag that she kept hanging around her neck through the entire trip. This included phone, wallet containing cars and cash, and a tablet.
At some point in the night she noticed that everyone on the bus was nodding off so she did the same. The strange thing about this for her is that she is one of those people that absolutely cannot sleep on a bus or airplane because the seats are not very comfortable. That is something that I can definitely relate to. It wouldn't occur to her until much later but she slept incredibly well in a fashion that she has never experienced in her life.
She woke up in the morning along with everyone else and noticed that her bag was a little bit open. She thought nothing of it because things happen, right? She did take inventory before getting off the bus and saw that her wallet, phone, and tablet was still with her.
It wasn't until after she had checked in at her hotel and was out having lunch that she realized that almost all of her cash was missing. All of her cards were there, as were her electronics and some of the cash remained but most of it was gone.
Someone had taken the time to go through her purse while she was asleep and leave not much of a trace of violation having done so. When she spoke about this to others that were on the trip they checked their wallets and a few of them had the same thing happen to them.
When they called to bus company to complain about this they already knew it was a lost cause but the bus company, who apparently must get this a lot, was full of a lot of excuses such as not owning the bus and attempted to push blame on the customers for losing the money themselves. Obviously the bus company wasn't going to take responsibility for this and given that she was now in Thailand, there were no real authorities to report this to.
I believe her when she says that she was gassed or drugged while on the bus and this would explain EVERYONE falling asleep in the night, including someone who this normally is a near impossible thing to have happen on its own.
In a way I kind of admire how crafty the thieves were because the victims were very unlikely to notice anything missing until it was too late to do anything about it. There is nothing to purchase at the bus stations that they drop you off at and she did later recall that the staff were a bit pushy to get people moving towards their minivans that were waiting to take the to the various lodging at their destination.
So here is what you can do to prevent this happening to you: You either wear one of those under-the-clothes belts to keep your money in such as this one.
This isn't common, but it happens more than zero times and to me, that is enough. So if you are the kind of person that this would seriously ruin your day, just buy one of these $5 belt things and then you wont have to worry.
My friend ended up losing a month's pay and well, I kind of got on her case for carrying that much money around with her in cash in the first place.