The issue with posts like that being 'proof' is that they're so easily manipulated. For example, if you're on Chrome, right click my post and hit inspect element and edit it to whatever you like, and then take a screenshot. Done. You can obviously also change the date. It's simple HTML source editing that any competent browser is capable of.
The following user thanked Clutch Hunterr for this useful post:
I live close to where the bombing was and it pisses me off that people think this was all a hoax. I mean there's no way that those two guys did this all by themselves, they HAD to have had some help, but Its disrespectful to the people who were hurt and effected by this disaster to claim that it was all a hoax. Everyone gets so caught up in these conspiracy theories...