I think a common belief that people have regarding umbrella insurance is that 'it will cover everything that my other insurances, such as auto, home, etc doesn't cover'.
And yes, if your friend slips in your house and requires medical bills, your homeowner insurance will cover it, and if it is not enough, your umbrella insurance will as well.
The issue with umbrella insurance though is that there are a lot of exceptions that prevent it from providing you coverage in case someone tries to take advantage of you civilly.
Why would someone try to take advantage of you in civil court? Outside of the fact that life sometimes just happens, many civil lawyers will take a case on contingency (aka they don't ask for money upfront, and will only get paid if they win). So an accuser can file a couple different suits at no risk to them, and hope that one sticks.
Back to the exceptions. If you look at umbrella insurance policies, there are many exceptions that prevent you from being covered.
Did you act with 'intent'? Intent is vague. For example, you may have intended to send someone a message, but you didn't intend to harass them, or you didn't intend for them to feel negative emotions from it. Regardless, the fact that you did intend to send the message means that a related case might not be covered.
Oh btw, most online interactions / disputes aren't covered under umbrella insurance.
Additional things to keep in mind are the difference between the duty to defend and the duty to indemnify.
Duty to indemnify means that the insurer has to pay out if you lose in a civil suit. And while they might do so in a simple case of someone slipping and falling in your backyard, because of the many exceptions mentioned above, don't except the umbrella to really act like an umbrella in your personal life. Umbrella insurance is more like a perforated cardboard slab rather than a true umbrella.
Duty to defend means that the insurance helps you with your legal costs. So the insurance might have to cover your legal fees, even if they don't have to pay out to the winner if you lose your civil case. See the potential problem here? Don't expect great representation legally if there is really no incentive for the insurer to actually help win your case.
