Just to put the above comment in some form of perspective . . . yesterday & today alcohol is forbidden to be served across the country. This is because some people are voting a week early in the election next weekend. The police went around bars, hotel & restaurants a couple of days ago informing them of the rule - and also the accepted way around the rule.
In practice this means that last night bars were shut, except for ones that must have paid to stay open. Restaurants were opne as usual and all restaurants were serving alcohol, same as usual.
However, if you order beer it was served in a paper cup - rather than having a glass & a bottle on the table. Cocktails still came in a regular glass as they don't look like alcohol.
So out of all the people in the beachfront restaurant I was in last night none were arrested, neither were any elsewhere on the island and I doubt if you'll find any reports of arrests of tourists drinking beer out of paper cups across Thailand.