Yes some people are in parks in groups. But people going on about this on social media are as likely to cause parks to shut as the people they're going on about. Stop creating a moral panic and chill the fuck out.

If they shut the parks we'll all suffer - and the people who are ignoring the guidance will carry on ignoring it by meeting each other behind closed doors anyway - while the people who condemned them will have talked their way into self incarceration. Triumph.

Stop locking the parks. Stick two uniformed coppers in every one and have them going round moving people on if they congregate or barbecue or whatever; arrest them if they get arsey. Not difficult, not resource heavy. Not rocket science.