From what I can tell, ACTA in its current revision wouldn't have much impact on the internet in the U.S., as it is pretty similar to the laws that are already in place here. Other countries may have cause to worry, however, if their home laws are currently less restrictive than those in the U.S.
The original version of ACTA truly was scary, hence all the "worse than SOPA" claims. But because of some leaked info from the secret meetings (thanks, Wikileaks!), there was a lot of early backlash, resulting in the fairly tame current revision.
There are still some questionable things left that don't deal with the internet. For example, ACTA could crush a lot of generic medicines, leaving expensive name-brand drugs as the only option for many people. On the other hand, that provision could theoretically take the unsafe, poorly made drugs off the market.