I have a beautyberry shrub I planted in front of our living room window maybe 7 or so years ago. Catalog I bought it from said it got 4' tall and wide. Well despite having been cut back every year after the first couple, the thing is now up to the first floor roof, at least 12' and probably 10' wide. It grew at least 6' higher from where I cut it off last fall. I'm going to cut it back again this fall, but probably try to dig it out in the spring and get rid of it. It is just totally outgrowing the space I put it in.
I'll try to find something a bit more disciplined to go there!
I looked now about how big they get. Depends on the species and I'm not sure about mine, but it is a purple beauty berry. I've seen anywhere from 2-4' tall, to 6-8'. But no where did I see anything that warned me this thing could turn into a monster!