Interesting that it exempts telephone calls. Why don't we treat other messaging services like phone calls?

The subjective element of crime (i.e. doing it on purpose) is fundamental also in the US legal system. If the person wasn't aware that someone else might see their messages, it should be hard to claim that they committed the crime.

According to Gemini, "Florida appellate courts have overturned juvenile convictions [based on this law] when the state could not prove the person subjectively intended for the record to be seen."