To the Original Poster who got arrested and charged with Riot: don't worry too much yet.
The Justice system is innocent until proven guilty. For you to be convicted, prosecutor needs to find enough evidence to convince the jury or judge "beyond a reasonable doubt". That means like 95% certain you are guilty of the riot crime.
There is no way police can gather enough evidence to make such accusations within 48hrs.
More probable is to charge you something serious and scare you. More importantly during probation period, while you await trial, prevent you from going to protest anymore.
So by the time the trial is over and your case is thrown out of court, it is hoped all these protests and uprising would have ended.