These plants grow everywhere. All of the hedges are full of with with lots of big thorns. Sometimes in the summer I see branches grow out into the path. What happens if you get stung? Are brambles poisonous?
Generally speaking, they are fairly harmless plants. There may be cases where there could be some sort of underlying issue a person has or a scratch from a thorn that gets infected but brambles are not poisonous.
Brambles also don't have the ability to sting. They contain large thorns, much like a rose bush does. Getting pricked by one may cause a fairly deep cut that will cause you to bleed for a few minutes but nothing more. The thorns are strong enough to pierce the skin but will break before they cause any serious damage worthy of stitches.
I wouldn't suggest you go running I to them but if you spot them on the path, just pick off the thorns and then snap the branch to get it out of the way.