@Patowalker & @Mike: totally agree, there is not the slightest inconvenience, at the contrary. There are mischievous people around in small planes, there are recorded cases of smuggling people and drugs, particularly to the UK, so it is only normal that controls occur; any correctly-minded aviator will endorse and support such controls.
@Pilot DAR: next time you come to Europe, give me a call, and I'll show you the police controls at airports, railways stations, and seaports (check Zeebrugge and/or Calais, there must be plenty of pictures and movies showing the extremities some people will go to). I bet you'll be quick to agree it is the least of nuisances to write down one's flying in a logbook, compared to the draconic measures applied in other modes of transportation.
On the other hand it must be said there are no registers of departures/arrivals at French non-controlled fields, yet I cannot remember reports of intense illegal activity there.
On a side note: my home field is next to the grounds of one of Belgium's main summer music festivals, Pukkelpop. Like at all those festivals, police helicopters are around all the while, and they'll often land at ours for a break. They are always made very welcome, and the few times I talked to those crews I found them of course very professional but on top of that quite enjoyable company. Of course they know how to be polite
But we don't consider police as intruders here, or as enemies of our privacy. Our CAA are much less popular! But that is a matter quite separate.