First of all, the addresses of anyone who makes campaign contributions are public record, so no one involved in political action at anyone's home is doing any major snooping.
But... there's a big difference between:
- Showing up at someone's house for a set time, to do a brief, planned, coordinated, non-permanently-vandalizing action vs. encouraging people to stop by a private residence whenever they feel like it to do whatever they feel like.
- Showing up to engage in street theater (usually campy, like caroling, covering a home with a giant condom, or creating a temporary graveyard) vs. publishing Tom Periello's private residence in a context in which other community members have already engaged in permanent vandalism and called for burning him in effigy (a tactic historically connected to lynch mobs and other extra-judicial violence)
- Holding a politician accountable for their actions and being clear on the policy changes we want to see, vs. holding a politician accountable for (exaggerated statements about) their beliefs and at times their very existence, it seems. For example, when ACT UP New York members put a condom on Jesse Helms' house, they were protesting his staunch refusal to allow people access to condoms to protect their health. They weren't calling him out for being Christian or exaggerating his position or suggesting that elected Christians have no business holding elected office. But tea-party bloggers seem to target people by saying, "they voted for health care reform, and therefore are socialists (or worse) and therefore should not serve in American politics." That's really different than holding a protest anywhere, the message of which is, "don't vote for healthcare reform because we think it's a bad idea."