Dude, Why's Your Bike Here?

i bought a bike yesterday -- so exciting!

imagine, then, my chagrin, when i took it downtown for the first time, thinking to run errands, locked it up on 17th and chestnut, and came back from the shops to find that some idiot had locked his bike next to mine with my brake cables in the u-loop of his lock!

omg! i'm a new biker, but even i know that that's terrible bike etiquette! i was so pissed! (and totally made sure to tell him so when he came back, ipod'ed, sunglassed, completely duh and apologetic enough to make sure to call me "honey" while he said sorry...)

what does one have to do for an uneventful ride in this town?