This is what happens when the power and reach of the state is not held firmly in check.
In America, the left blames Bush for giving law enforcement and intelligence agencies powers that have the potential to be used as tools of tyranny. Such powers are dangerous. They should not be conferred without strong cause and never on a permanent basis. To be sure, there have been...problems... here in the states with the FBI and other agencies using their new powers in ways that are questionable in some cases. But so far at least these powers have been mostly used for the purpose they were intended.
Meanwhile across the pond in a country where the left is so entrenched that its citizens are unaware of any other philosophy (I'm being generous today), the government is blatantly abusing powers that it has granted itself in the name of fighting terrorism.
In America the left screams about abuses that aren't happening while the leftist government in the UK actively and grossly engages in precisely those sorts of abuses.
I suspect that the biggest issue that the lefties have when it comes to the patriot act is that they're not the ones in control of the state yet. Were they in power you can be quite certain that they would not only be fully in favor of it, but they would expand it greatly.