The bike has now gone, went about 10pm last night.
To answer the question about why it bothered us, it was blocking thw pavement and people going past our house with buggies couldn’t easily get past (narrow pavement of about a metre and a raised kerb on the road side) as it looked like we had sanctioned that damn fool putting it there.
Even if they chained a bike to your first born son, it’s still totally unacceptable to tamper with a QR skewer.
Fingers crossed they leave it there on a regular basis, OP’s head explodes with rage and the rest of the street ignores the minor trivialities of modern life.