Not just Bitcoin thieves, but just thieves in general. By trade, Im a locksmith. I'd like to give out a few pointers for my USA people who live here. European locks are different from the States, so Im sticking to locks you'll find at a home depot or similar.
Ill start off with what NOT to buy.
SMART KEYS.
If you've purchased a Kwikset Smartkey system or a Baldwin Smartkey system. Throw them into the garbage. If you don't know if your lock is a smartkey or not, just look at it. Smartkeys have a tiny hole on the cylinder. Look at the image of the deadbolt on this post. See the tiny hole? That's a smartkey lock. These locks are designed to make it convenient to rekey a lock, but the materials used inside the lock are cheap metal. Anyone can basically stick a flat head into your keyway and with a wrench or vice grip, grab the screwdriver and turn it open with minor brut force. Don't believe me? Get on youtube and see how easy it is. As a locksmith I CANNOT recommend these locks to anyone.
Ok so what should you buy:
Well that depends on your budget. So ill break it down by price range.
$10-25 : This is honestly not worth it. This is most likely what you have on your door right now and a thief can easily bump his way into this lock which you can order online. But if its all you have, then I say go with a Toledo Lock. They are new in the game but what makes them good is their keyway. They are using a Yale keyway and there are barely any Yale bump keys. They will be forced to pick the lock which depending on skill level, they will be standing by your door for a couple minutes and hopefully a neighbor notices.
$25-50
At this price range you can afford a lock with a heavy duty housing. The Schlage brand offers a deadbolt with a robust one piece housing for the lock. These can still be bumped, and this won't stop a skilled thief, but it will slow him down enough or make him use loud making tools alerting neighbors.
$100+
If you want a lock that cannot be picked or bumped, you need a Medeco M3 lock. These have been the top locks for a long time. If I wanted to drill this lock, I would have to make sure I have one or two drill batteries, and a bunch of brand new drill bits. They are expensive, but so is all the bitcoin in your wallet.
In conclusion, your locks are a very important part of your security to protect your bitcoin or crypto. Remember that you're your own bank now and it's up to you to protect it.