Whilst not condoning steroid use, I think a few people on here are getting confused between abuse and use. Steroids cannot be classed as one drug in terms of health dangers, for example oral Dianabol is much worse than injectable Nandrolone.
Just to keep things in perspective, if you look at the popular 'dependancy Vs health risk' graph, steroids are way down on the list, alcohol and even tobacco is much higher.
graph here
In most cases, try and view the health warnings of drugs much in the way you would look at the contraindications on the back of a paracetemol packet.
Also, I think I remember learning there were no known provable links to aggressive behaviour and taking steroids, too many variables, but I have had enough stories, on here and personally, that leads me to believe there is a link.
Even so, don't be silly, just get your muscles the old fashioned way, hard work!