AirBnB's guarantee doesn't affect this at all. Here's an example:
You rent an apartment and have a standard lease that forbids subletting. You travel a lot on business and decide to rent out your apartment for $150/night five days a month anyway. That's $750/month, or $9,000/year, in your pocket pre-tax. Not bad, but....
One day, you rent to an individual who happens to be a heavy drug user with a criminal record. You don't know this because you didn't perform any due diligence.
When your guest is confronted by one of your neighbors about a noise issue, he brutally assaults your neighbor. During the assault, your neighbor suffers major head trauma and is rushed to the hospital, where he undergoes emergency surgery in an attempt to save his life. Following the surgery, he is comatose and if he recovers at all, will require months if not years of rehabilitation. In the best case scenario, the doctors believe he will likely have some permanent brain damage that may prevent him from living a full, productive life.
When it comes to light that you were violating the terms of your lease and renting your apartment to complete strangers in exchange for money without doing any real due diligence on your guests, it's very likely you'll be sued by the victim's family. Needless to say, given the amount of damages you may owe if you're not successful in defending yourself, you're going to need a great lawyer. They don't come cheap. AirBnB's $50,000 guarantee? That only applies to damage due to vandalism or theft, but even if it applied to everything, won't even cover the cost of the victim's initial surgery.
Obviously, this is an extreme example, but it's well within the realm of possibility. There are plenty of other scenarios, less extreme, under which an individual could conceivably be personally liable for damages far in excess of what they will ever make using AirBnB, and far in excess of what AirBnB says it will cover.
By the way, AirBnB's guarantee is almost certainly not an insurance policy, even though the company (intentionally or unintentionally) is going to confuse people who don't understand the difference between a guarantee and an insurance policy.
As far as I know, AirBnB is not registered as an insurance company in any state, and I doubt very much that a legitimate insurance company would sell a policy for most AirBnB rentals without, at the very minimum, proof that the host has the authority to sublet and that he or she is not violating any local ordinances that apply to rentals and hotels.
This scenario seems pretty far-fetched. Are the even any examples of people being sued where they knowingly allowed a violent person to reside at their apartment, and that person then assaulted a neighbour? The fact that the violent person is a paying customer does not appear to change the duty of care owed to neighbours.
Under premises liability law, a tenant is generally responsible for personal injuries to guests, invitees and others (who are legally on the premises) if the tenant had control of the premises or was responsible for creating the dangerous condition that led to the injuries. IANAL but a quick Google search will provide you with the relevant statutes and case law.
If you sublet your apartment to a third party in violation of your lease and you fail to take reasonable security measures (verifying identities, conducting credit and background checks, signing agreements, etc.), you should expect to be sued for negligence if and when something goes wrong. Might you successfully argue that the injury in question was unforeseeable even under these circumstances? Sure, but you'll still lose because making that argument will be costly.
Finally, even if you somehow believe that there's no risk in subletting your apartment to strangers, you should consider alternative liability scenarios, like your guest suffering an injury while staying in your apartment. This too makes AirBnB a juicy target for cons, as it would be relatively easy to stage an accident with the intention of suing the host.
The net-net:
1. Being sued is an expensive hobby and anyone renting out his apartment to strangers to pocket a few extra bucks is always one guest away from discovering this.
2. There are good reasons most landlords forbid subletting.
You rent an apartment and have a standard lease that forbids subletting. You travel a lot on business and decide to rent out your apartment for $150/night five days a month anyway. That's $750/month, or $9,000/year, in your pocket pre-tax. Not bad, but....
One day, you rent to an individual who happens to be a heavy drug user with a criminal record. You don't know this because you didn't perform any due diligence.
When your guest is confronted by one of your neighbors about a noise issue, he brutally assaults your neighbor. During the assault, your neighbor suffers major head trauma and is rushed to the hospital, where he undergoes emergency surgery in an attempt to save his life. Following the surgery, he is comatose and if he recovers at all, will require months if not years of rehabilitation. In the best case scenario, the doctors believe he will likely have some permanent brain damage that may prevent him from living a full, productive life.
When it comes to light that you were violating the terms of your lease and renting your apartment to complete strangers in exchange for money without doing any real due diligence on your guests, it's very likely you'll be sued by the victim's family. Needless to say, given the amount of damages you may owe if you're not successful in defending yourself, you're going to need a great lawyer. They don't come cheap. AirBnB's $50,000 guarantee? That only applies to damage due to vandalism or theft, but even if it applied to everything, won't even cover the cost of the victim's initial surgery.
Obviously, this is an extreme example, but it's well within the realm of possibility. There are plenty of other scenarios, less extreme, under which an individual could conceivably be personally liable for damages far in excess of what they will ever make using AirBnB, and far in excess of what AirBnB says it will cover.
By the way, AirBnB's guarantee is almost certainly not an insurance policy, even though the company (intentionally or unintentionally) is going to confuse people who don't understand the difference between a guarantee and an insurance policy.
As far as I know, AirBnB is not registered as an insurance company in any state, and I doubt very much that a legitimate insurance company would sell a policy for most AirBnB rentals without, at the very minimum, proof that the host has the authority to sublet and that he or she is not violating any local ordinances that apply to rentals and hotels.