If I take somebody's property without consent, with the intent of keeping it, it is theft.
If I take somebody's property without consent, but return it to them immediately, what law am I violating? Assume I return the property in perfect state, completely undamaged.
- The Ministry Of Defence (MOD) has placed No Trespassing signs near a military base. I remove the signs and return them to the headquarters of the MOD¹.
- Someone has attached a trail camera in the forest. I take it down and bring it back to the owner.
- The local authority has put a sign indicating through-traffic through my street. I remove the sign and deliver it to the local authority offices.
- Scientists have installed measurement equipment to monitor something. I remove the equipment and return it to the institute owning it.
I'm a nuisance in any case, but what law am I violating, if not theft?
¹ I heard about it in a sort of cat-and-mouse game between British peace activists and the police:
1. A group of peace activists walked passed a "No trespassing" sign near a military base, in order to document (and perhaps disrupt) activities. They are arrested for walking past a "No trespassing" sign.
2. A group of peace activists remove the "No trespassing" signs. Others walk past the location of the sign. They say that they have not seen the "No trespassing" sign, and can apparently not be arrested for violating it when the owner has not clearly indicated "No trespassing". However, they are arrested for theft (or conspiring to steal) Ministry of Defence property (the signs).
3. A group of peace activists remove the "No trespassing" signs obtained at a military base, drive to the headquarters of the Ministry of Defence, and deliver the signs at the reception. Meanwhile, others walk past the location of the sign. Police are not sure what to arrest them for, for they have not stolen the signs and the "No trespassing" is apparently not valid when not clearly stated.