Lol...it will take some doing to open that door!
I've got alarm on mine...not overly difficult to open the actual door, get in and silence the alarm, but one has to first shift load of logs, fence panel and bags of compost to get to the door...and then everything valuable inside is been chained together and locked many times over...
Good security is one thing...but trying to get one's machinery out is other..
You just look at the effort it takes to get in and you think 'bother'..and put spade in use instead.
Thanks for the idea ..I've got very similar iron gate 'spare' that would do just a job...but what it weighs, it might bring the shed down too!