To whoever pried the letters off the 35W Bridge Memorial: There are several possibilities to explain what you did. Let's go through them one by one.
1. You're a good person. Dagnabbit, you're a great person. You were coming back from the orphanage, where you donate your time, money and extra organs as needed; you were en route to the blood bank, where your rare type is in such demand you go to different banks under false names to give more than you should. The blackouts from blood loss are annoying, but when you feel yourself getting weak you just get on a bus and sleep it off for a while. Sure, your pocket gets picked, but if that guy didn't need it, he wouldn't take it. Anyway, you were right by the memorial, when you saw a puppy in the road, terrified. Cars whizzed past; the poor trembling beast didn't know which way to go. You couldn't reach it. It might run into peril if you ran to save it. Whatever could you do?
That's when you saw the memorial. Quickly, you scanned the words, tallying up the letters -- yes! Yes. There were enough. Whipping out your pocket knife -- given to you by the pope for your anti-malarial work in Sudan -- you pried off the letters, begging forgiveness as each one popped off. Quickly you arranged them to form an ancient spell which summons a genie who grants one wish, at the cost of your immortal soul. The genie saved the puppy -- and the horrid demon took the letters so no one else may disturb his rest. With a harsh and brittle laugh, he vanished in a puff of stinking smoke, and you knew you'd see him again when he came to collect his price. But the puppy was safe. You walked back to the orphanage and gave it to the kids. They wanted to name it after you, but no. Heck, just doing your job.
2. You're an idiot. You sorta just got caught up in something, you know? It's not like anyone was planning to vandalize the memorial; it just happened. So that should count for something, right? It wasn't like, premedicated. All of a sudden you were there, and your buddy's laughing and popping off the letters, and you're like, whatever, and so you did one, too, and another because they were your initials, and your other friend is shooting it with his cell and he's all like, This is just going to blow up on YouTube, dude. There was something in the back of your head that said putting this up on the Internet isn't smart, but everything has to go up on the Internet, doesn't it? Otherwise, how is anyone going to give it a Like on your Facebook page? Pics or it didn't happen, as the saying goes.
Anyhow, that was just one thing, and it's not like you did another and afterward you all just went to White Castle, and you had like the onion rings? They were cold and the punk manager didn't want to give a refund because you ate them all. You don't know what the big deal is anyway. It was just a prank, and there were lots of letters left. It's not like you're a criminal or anything.
3. You're a bad person. This probably comes as a surprise, because everyone likes to think he's a good person. But there's something wrong with you. You lack empathy. You lack the ability to see beyond yourself. You have no sense of community. There may be a reason for this -- deep-seated, incoherent rage over something in your childhood that provides an ever-present sense of justification. Maybe no one gave you guidance as a youth. Many possible reasons. We don't care. Not when you do this. We could learn that every day of your childhood someone stole your alphabet blocks, and it wouldn't matter. If you didn't think it was wrong for you -- and few things are, are they? -- you knew it was wrong by the standards of the community, or you would have popped them off in broad daylight with a squad car trolling past.
You ought to be ashamed. Try to imagine what that feels like. If you can't, find a good person, and ask him to describe it.