I've read the article thanks, her visa being invalid isn't the reason for her being arrested it is simply the reason for her coming to the attention of the authorities. Once the guy was apparently rude to her (I guess the attitude towards women there can be dubious) she's then filmed him (illegal) and he's asked about her alcohol consumption (also illegal)... those are the two reasons we've got for her arrest - you'll see also that she had a blood test (again related to the illegal alcohol consumption).
Yes people drink there all the time, no it isn't legal for tourists. So long as you have no grounds for the authorities to have to deal with you then no one is likely to care...
I never denied that drinking was a factor in her arrest, I was just point out that the article and this thread is only focusing on the drinking.