Yesterday we discovered that the lock on the door to our apartment had been tampered with through the night; there were obvious tool marks around the edges of the keyhole.
For the past two years, our area of town has been the target of numerous incidents where a male intruder went into households and watched (and in the more recent cases, touched) female occupants while they were sleeping. Although the fact this was a forced entry didn't match up with that scenario, it was a little too suspicious that it happened when our male roommate was spending the night somewhere else.
The rational part of me knows that no one got in, and hey, the lock obviously held out long enough for the person to give up, so we're safe. But in a city that seems to have had a drastic increase in crime over the past few months, it's still very worrying. I am unimpressed.