If they are sliding patio doors, especially aluminium and the sliding door is the outer one!!
Crooks no that they can be lifted off there rollers easily even while locked
( i many time attend a break-in with the sliding door just sat at the side undamaged, and the house emptied through the huge hole it leaves.)
Dont panic all you need to do is stop the door being lifted ... fit a patio pushbolt or 2 in the right place and hey presto they go somewhere else
If they are double opening french type doors either wood or platsic they too have there weaknesses which need attention..
I knew growing up in salford would come in handy one day