What is the ruling on capturing unencrypted ADSL signals and accessing the internet without the owners' permission, knowing that this only costs the ADSL owner his monthly subscription?

It is not permissible to benefit from another person's private internet service without their permission, based on the hadith: "Indeed, your blood, your wealth, and your honor are sacred to you." This is considered an aggression, a betrayal, and a usurpation, as it involves taking another's property without their consent. Usurpation is taking any property without the owner's consent, whether it be a person, money, or benefits, and this includes trespassing secretly or openly. As for public wireless networks established by the state, there is no harm in using them due to the general permission granted.