fence towards publics access are: at least 2,4m high
fence towards your neighbour: no restriction I think; but check it first.
Note the difference between "Barb Wre" and "Razor Wire"..crooks DO mind... ;o)
here are some helpful topics spread, search for trespassing or "razor wire"
one link:
http://www.theanswerb...l/Question907448.html
Build some passive security features which annoy the guys, like motion triggered floodlight (out of stone through reach) and fake cameras.
Reinforce your fence, so they need heavier tools, plant blackberries (no joke)
some advice on this link, found it in here:
http://www.protecting...evention-methods.html