What an interesting card! "Interesting" does not necessarily mean "good," so let's take an in-depth look at the card and see where our opinion lands.
If we reduce the card down to its barest interaction, devoid of context, you're essentially paying one click and one card to bring the corp's agenda score down by -1, since most of the time the corp doesn't ice up archives. Unless, of course, you're Noise, or they're Industrial Genomics, or the cards Keyhole/Security Testing/Sneakdoor Beta are on the field.
That's not too bad, all things considered. But how useful is it really? Time to actually add some context and see. Here's the interactions and strategies you'll need to keep in mind when considering this card:
-For Anarchs with MU issues, this may be one of the best ways of dragging out the game... In other words, halting Fast Advance decks. Best case scenario, they'll purge and destroy your graffiti when they're at 4 or 5 points, signalling that they more than likely have an agenda in hand. Worst case, they score all the points they need and then purge after, which buys you a single turn at most. Thankfully, this is FA we're talking about here. That single turn could very easily mean the difference between a win or loss.
-Playing a second (or third) of these when one is already in the corp scoring area is probably a waste. Since a single purge is all it takes to get rid of all copies of Graffiti, unless -1 point isn't going to stop the win by itself, two or three of these is a overkill. Still, you using two or three clicks to make them use a whole turn isn't that bad of a trade, really. But definitely not a great one when you consider that you also used two or three cards on top of that. And even worse if they don't even use their whole turn and just whip out CVS.
-On the note of CVS, this card doesn't seem all that good in an already virus heavy deck. For example, if you're Noise, or any other Anarch who'll obviously be using a ton of viruses (ahem), the corp is already waiting to bust that CVS out at the earliest opportunity to ruin your day and set you back. So since they're already counting on purging viruses, perhaps multiple times over the course of the game, you could almost argue you're wasting clicks and cards to encourage them to do something they were going to do anyway! However, if this was in, say, a MaxX deck, where the only interaction CVS had was with Political Graffiti itself, the corp is probably likely to toss out such a card, thinking it to be useless. Thus ensuring three clicks will be devoted to getting rid of it. Nice.
-It's an event. Not a program, or a resource, like Clot or The Source. This means you can use Same Old Thing to put it right back in the corp's scoring area as soon as they purge it. This also means that unlike Clot or Source, it has hardly any ways to tutor it, while those other two have so many, such as SMC or Hostage. It also misses out on the instant speed interaction that Clot has with SMC and Clone Chip.
-This card has anti-synergy with Iain Stirling, depending on the board state. Which is funny enough in itself, but definitely begs the question: why on earth are you spending his precious few influence on this?
-Finally, and most importantly/unfortunately, the corp can very easily not care about this card, even if all three are in their scoring area. This card doesn't close scoring windows or make them harder to open. It doesn't actually take away points they've amassed either really. It just makes it take a little longer for them to activate. Heck, if the corp's main plan is flatline, they'll just see this and laugh. This card hardly even exists until game point, and then at most it just makes the game take one turn longer than it would have. Which it might not even do, if in that last desperate glory run to score you hit a CVS, allowing them to win on your turn. Talk about painful.
So far be it from me to render judgment over whether or not this card is "good," but from where I'm sitting, it ain't. In an Anarch deck it barely slows things down, and not even as reliably as their other in faction card, Clot. Outside of Anarch, you're barely slowing things down for a whopping three influence (or more)! I don't expect this card will see a lot of play. Perhaps some, but not a lot.