Yikes, very scary. I would be worried about them coming back for a second go (don't want to worry you but it's the suspicious way my mind works). Do you think it was your bikes that were being targeted, is it likely that your bike 'habit' could have attracted the attention of the thieving scumbags or was it likely a random attempt at breaking in? It sounds a bit too specific and determined to be an opportunist trying their luck.
What are you going to do straight away to improve the security? You need this securing before tonight in my opinion and if you can move your bikes to another location for a couple of weeks then I would recommend it (I am saying this as I assume, like me, that you will have a fleet of mid range bikes that if having to be replaced would cost a few £thousand to buy new?).
Do you have any kind of local homewatch or gossip network? It would be worth finding out if anyone else nearby was also 'visited', at least you will feel better knowing it wasn't just you and your belongings that were the sole target if this were the case.
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, thieving scum 
and 
in the end. 
