In Sunday’s Championship derby between midlands rivals Birmingham and Aston Villa, a fan was able to run onto the field and assault visiting Villa star Jack Grealish. The supporter has subsequently been banned from attending soccer games and will be spending the next 14 weeks in prison, but his cowardly actions represent a worrying trend in British soccer.

Incidents of violence, racism, antisemitism and antisocial behavior have been all evident all season long—which may suggest we are taking steps down the path towards the dark days of hooliganism in the 1970s and 1980s.

Just hours after the Grealish incident, an Arsenal fan ran onto the field and assaulted Manchester United’s Chris Smalling. He too has been charged.

Unfortunately, these cannot be treated as isolated incidents. This season, we’ve also seen a banana thrown at Pierre-Emerick Aubameyang, a Chelsea fan launching racial abuse at Raheem Sterling, anti-semitic chanting, hooligans fighting before Everton’s clash with Millwall, and glass bottles being thrown on the field in Scotland.

British soccer had a massive problem with hooliganism in the 1970s and 1980s—and there are worrying signs that that kind of behavior is returning. Back then, when the game was very different to the sanitized, family-friendly product we watch today, the problem was dealt with by segregating crowd and erecting fences at English stadiums.

However, those fences came down after the Hillsborough tragedy, and since then, there has been a tacit agreement that fans don’t enter the field to commit violence. That tacit agreement seems to have been broken.

The problems are undoubtedly a reflection of the angry and divided nature of western society—Jonathan Wilson notes in Sports Illustrated that hate crimes in the UK have doubled in the past five years. While soccer cannot fix societal issues like this, it can certainly go some way to preventing incidents like this from happening on the field.

For starters, the governing bodies must start laying down the harshest punishments possible to show that unacceptable behavior won’t be tolerated. Birmingham, for example, should have points deducted and some games played behind closed doors to make sure fans get the message.

Any team whose fans are caught engaging in violent, racist, homophobic or hooligan behavior should face similar issues.

While we are far from the darkest days of hooliganism, we are currently taking stepping stones back towards it. So, for the sake of the sport, action must be taken.