well i never heard of it happening, but i heard that in order to break it you really need to hit it hard, you almost have to do it as if you'd do it on purpose.
i know I'm too, since i live in an apartment style condo unit and didn't want it breaking and then leaking beneath me. That's why I got an acrylic one, no seems to worry about.
I broke a 10 gallon once by accidentally tipping a cushioned desk chair over while messing with the wires underneath the desk. The top corner of the backrest hit in the center of the front pane, resulting in a huge hole and all the water and fish and plants draining onto the floor.
It is really surprising at how much water is actually in a 10gal when it is soaking into your carpeting. I just doesn't look like much in the tank. That kinda makes me paranoid about my 120gal breaking somehow.
I also read somewhere that it is not a matter of if the silicone gives way, but when it will. Not sure if this is true, but am pretty sure that these things are not meant to last forever.
I had a 70G glass that was over ten years old and then a 90G glass that was near eight. Never a problem with either unless you count a golf club through one as an issue with leakeage.
Well I mean its freakin tempered glass on most tanks, if you manage to break that your pretty good. Sliding glass windows are tempered and you can slam a chair against them. But I do often wonder about that silicon.
We wife cracked a 3 gallon acrylic eclipse tank we used for a quarantine tank when cleaning it in the sink once. We taped it so we could still ise it until the a replacement tank came in the mail. There was minimal leakage.
My wife busted a 10 gallon one time. She threw a hard dog toy that took a bad bounce and his the tank. I've had rock slides, dropped rocks, etc and never had an issues. My old 110 was moves a whole bunch of times and never had issues.
My wife was in charge of holding the water hose in my 125g for 1 minute while I ran to get some chlorine remover. Somehow she managed to let the hose slip and the brass end hit my 40g tank when it fell out cracking the side. It cracked in about 10 places, but amazingly it did not blow out. I still had a good bit of water to clean up though. I've busted several drilled 10g tanks. 10g tanks have such thin glass that they are really easy to break. I have had silicone to get old and start to slow leak, but never had a pane blow off. I do know one guy whose bottom fell out of his tank. I heard that was a mess. It seems like I heard it wasn't tempered and he had a lot of live rock in it.
Unless the wife is a reef geek also not possible. Mine makes faces when it comes to tank stuff. Atleast she is willing to feed the critters and fill the top of container when I travel. She will not touch the skimmer, or kalk stirrer.
As far as leaking goes, my oceanic 75 is 17 years old and no leaks. Original silicon. It has been cichlid tank, oscar tank, and now a reef tank. It was dry from 1999-2006 though, if that matters.