Not volunteering information to a LEO is fine. Lying to an LEO is not fine. Putting aside the ethical implications of lying, the concern about getting arrested - or worse - is a very real risk. I am reminded of a story I heard about a Class III dealer who was transporting MGs interstate for a gun show. He was stopped by the state police for a traffic violation (probably a broken tail light). When the officer asked if he could look in the trunk, the dealer said yes. When they opened the trunk, the officer practically had a cardiac....Lying in the trunk on blankets were a bunch of MP-5 SMGs. The officer jumped back, drew his sidearm, ordered the dealer to assume the position, and called for back-up. The dealer cooperated, knowing that the officer had a drawn gun and was nervous as heck. When the officer's supervisor rolled up, everything got straightened out because the dealer had all the right paperwork - and the supervisor knew enough about firearms law to recognize that everything was in order. The officers thanked the dealer and sent him on his way. Now, imagine how this could have turned out differently if the dealer had NOT had legal MGs with the proper paperwork, or had lied to the officer? BANG, BANG, BANG.
Also, need I remind you that transporting or possessing contraband weapons (unregistered AWs, MGs, SBS, SBRs, DDs, what have you) is NOT fine according to our Attorney General. This kind of felony will result in a LIFETIME ban on firearms possession. Great for a gun enthusiast, no? Remember that in California, we have Three Strikes (second strike doubles the term, third strike for ANY felony (including tax evasion) is 25 to Life. Our state prisons are not exactly vacation spots. Think about that before considering doing anything so blatantly illegal as attempting to sneak and unregistered AW into California.
When the registration hit, I registered everything - even guns I didn't think needed to be registered - just to be on the safe side. Since I already own NFA firearms and have a CCW (and once carried a badge in another state), it wasn't like I was already in the FBIs and everyone else's database. Better safe than sorry from a legal standpoint. And yes, if there is a confiscation someday, they'll know where to look. So what? If things get that bad, we'll have more things to worry about than our guns - like the rest of our freedoms.
Comply with the law, as stupid as it may seem. Then vote the idiots out who wrote these laws.