I was developing CTI interfaces quite a few years ago and as such was using the companies phones lines to do testing.
Boss came into the office and told me to stop testing as the latest invoice was extremely high.. As my testing was aony a few phone calls using local numbers I was a little dubious at being the cause of the high amounts.
As anyone would do I then inspected the bill and call up our provider in order to have further details..
Reality hit : The expenses were in fact associated with a mobile number within the company that was using SMS texts to pay for Porn..
Guess who's mobile phone was being used, oh yes it was our favorite Pointy Haired Boss...
I confonted him with the fact the someone was using SMS to pay for Porn access without mentioning the number that was being used. He quietly dismissed me from his office and said he would investigate himself as to who was using the companies resources in a such a manner.
I also had the logs from our Firewall which left no doubt about the time spent browsing Porn from his office machine.. ( I didn't tell him about that though)
I was allowed to continue my testing and next months bills were already back to normal....
( I don't now if SMS are still used to make payments because that was several years ago, about 12 and thing have moved on since, thankfully)