The only reason why this guy gets away with these tactics is because the police agree with it and low key would be happy to do it themselves. Not because they appear to be legal.
If this guy gets away with it, the homeowner likely would too, unless he's got some sort of special payoff scheme to the police.
From what I can gather from the article, it does seem to be entirely legal. He never forcibly removes the squatters, just makes their life annoying and difficult, and they usually choose to leave. He also doesn't attack anyone, and only uses the weapons for self defence.
I think any property owner could do the same, but it's just a risk that they don't want to take. Who wants to get up close to a (potential) knife wielding meth addict?
Yeah. I think the additional trick is that squatters often have a fraudulent lease. That makes it owner vs. tenant, and the police have orders to err on the side of not facilitating an illegal eviction. The owner could attempt to owner-occupy the property, but there's no document for that and there is a lease. So when the police show up, the owner is very likely to be the one removed or arrested.
The sword guy makes it tenant vs. tenant, so neither party has that formal advantage. Of course the police know the game, but they're generally happy with the workaround.
In the article they interview one of his customers and the guy basically says he is just a finance nerd that likes to ride his bike and hug his wife and he has no experience with potentially violent situations. So, I'm imagining a lot of customers are like that.
If this guy gets away with it, the homeowner likely would too, unless he's got some sort of special payoff scheme to the police.