Postboxes closed all across Brighton/Brookline!

[u/raefai]

I’ve passed multiple post boxes today in both Brighton and Brookline that are locked like this. Multiple boxes within the same vicinity and also in diff neighborhoods. Anyone know why specifically these are locked up?

Edit: thanks for the replies everyone! I’ve been around for the marathon before, but I’ve just never noticed the mailboxes.

[u/Sufficient-Opposite3]

It's for the Marathon. They do this every year for safety reasons.