Found this on the net...Whoever is from Estonia should understand the point of this joke 
Police
Estonia is known for its safe streets and lanes. To further worsen the situation, Estonia's government has unofficially hired some gorillas, to hunt down unsuspecting civilians and drunk Finnish tourists. These gorillas are known as F.A.L.C.K. - Finnish Agents & Libyan Cat Killers. They have efficiently evolved with the situation in Estonia and are known as the second threat to society (the Parliament wins the most-dangerous-adversary award.
Many Estonians have heard about a new threat to the Empire - a secret project a.k.a The Naabrivalve (the same as Big Brother). Already, hundreds of civilians have been involved in this soon-to-be-big project. The people involved (also known as the NV-s) become very weird, they want to attack everyone and in most of the cases they want to mate with everything that moves (sometimes even with things that don't move!). So you'd better watch your back when you happen to see a "Naabrivalve" sign on a house.
You can easily recognise the participants of The Naabrivalve by staring them in the eye. If they attack you, rip you into pieces and afterwards feed your body parts to their dogs, then you've found them. The NV-s are most vicious at night, at that time they can even attack their relatives who have come to lurk behind their door, (maybe just come to visit,) so watch out by all means! And also thousands of mail deliverers have been killed due to this aggressive overwhelming project. They show no mercy.
Other important tweaks in the Estonian Security System. The policemen (in Estonia known as the mendid) are trained very carefully under the surveillance of extreme professionals. No food is given to them during the training period (which is only 20 years) and the mendid are only allowed to drink contaminated water. They also have to cope some extreme conditions such as 200 degree heat (on sundays) and cold 100 degree below zero (on mondays). During the other weekdays they spend some quality time in Sahara desert and learn some useful skills to fight crime in Estonia. All in all the mendid are physically very tough and mentally as well. Sometimes they seem to be a bit stupid but they only pretend that. Unfortunately the mendid are not good enough to keep crime out of Estonia. Maybe it is because of the little food they are allowed to eat but maybe it's just that the criminals have better preparations.
The mendid usually use wrenches to fight criminals. But sometimes they are even allowed to use metal sticks
