I keep hearing this, and its beginning to sound like the teacher from Peanuts..."Wah-wa-waa-wah-wah-wah." I implore you to produce a verifiable, citationized court case that resulted in the conviction, or civil forfeiture due to the removal or modification of a passive safety device.
The case wouldn't, of course, be because of the lock removal. It would merely be a point harped on by counsel ad infinitum and would be one of many facts that determined the amount of the judgment.
Listen, I think everyone here has heard of the now infamous case of the bad guy trying to break into a house by crawling on the roof, then he hits a soft spot, and crashes into the house, and then sues the homeowner for negligence and wins. It's a true case. In fact, it's a series of true cases, because this type of situation is almost always a slam-dunk winner for the injured. What he was doing there has no relevance to the court vis a vis your actions/negligence; ie. the bad guy's actions are separate from any negligence displayed on your part.
I think most everyone here would throw their hands up in the air and cry "BULL****! THAT CRIMINAL DOESN'T DESERVE A PENNY!", but that's simply not the case... and just as it isn't the case that legal gunowners don't get sued (and lose) when they defend themselves in justifiable situations. You don't have to spend much time in law school to see how a typical jury of idiots can conclude that the actions of modifying a weapon so that you are removing a safety device are negligent. And if you have spent time in law school you will know that, given the right jury instructions, jurys will automatically come to this conclusion, even if they are in the "BULL****!" crowd, because the instructions can be so specific as to elements (if they did X, you must y) that they don't get to apply much real logic to their own decision.
I think part of the responsibility of being a gun owner goes beyond keeping the gun away from children and knowing what lies beyond your target. It includes knowing what can and will likely happen to you should you dischagre your weapon at another person. I, too, wish we lived in a country where you could shoot the rapist in your houes and the cops/DA would just say "good job" and leave you alone. Indeed, sometimes this happens. But it is not the majority.
Every gun owner should understand that when they shoot someone, it is going to cost them anywhere from $20,000-$200,000. And I am not even talking about a judgment. It could cost you $20,000 to get the ridiculous case thrown out. Easily. I have a brother in law who had his parked car rammed by a drunk driver. The impact caused his car to hit another car, and because he had money and the drunk driver didn't, he got sued for damages. Yep, ridiculous case. Yep, about $25 grand to get a lawyer to make it go away.
Should you live in fear of lawyers? No. Should you not shoot the BG because of fear of a lawsuit? No. Should you alter your life to avoid a lawsuit? No. But should you walk around pretending like you won't get sued/lose big money when and if you have to shoot someone. Also: no.