I'm not a terrorist. But do you really want to take the position that it's impossible for a terrorist to pull off an act of terrorism and get away with it? Totally and completely impossible? Really??
I can't describe what they would do, but to deny it's possible at all isn't reasonable.
Well let me walk you through how it couldn't have happened then. The entire 26 mile route is swept for bombs prior to the race starting. After the sweep, the finish line is heavily guarded for most of the race when political dignitaries are present. The terrorist has a small window of opportunity to do anything, and they exposed exactly what that window is. That will be addressed next year as no one will be allowed to have a bag without it being searched.
Now here is the part where they will get caught regardless. All of the businesses in that area have surveillance cameras at the front of the business on the street. While it may take a while to find the party who dropped a bag, they will find them and we will see their picture. Sleeper cell? means they live here and people know and will identify them. Temporary visitor? doubtful, as it would be difficult for them to obtain the materials they need so quickly. Even then, there are surveillance cameras at airports/train stations/etc. They will pinpoint eventually how they came here and left.
Suicide bombers? Whole different story. They could do it, but they would die doing so and thus the whole "caught" thing is a non-point.
Large liberal cities have gained a reputation for being overly PC, which in a day in age when we've got muslim crazies that would like to kill us, isn't the time to hang onto that view. It takes more than just cameras, it takes observant people who are willing to accept that certain profiles need to be watched more closely than others. Nothing that's happened this past week has changed my viewpoint that their PC will continue to blind them. I've said for a while that if I'm looking for a place where I can attack the USA and not raise suspicions, then SF would be #1 and Boston would be #2. It's not you, OK. I'm not addressing you. It's these whacked out lib PC nuts that have infected the area and refuse to live in the real world.
Profiling needs to be done - agreed on that 100%, and I believe anyone/student coming here on an education visa needs to be held to a much higher standard and watched closely. That said - Boston houses hospitals that people come to from all over the world for treatment, and we have many visiting scientists here doing research (not to mention the large number of students here on visas - legitimate students). Boston is very diverse. Is that wrong? No, of course not. However, this country does give foreigners too many liberties at our detriment.