The real question in this post is wondering if there are different sets of rules for a domainer selling a trademarked domain vs a registrar / auction selling a trademark name.
Generally, no. Registrars are immune from ACPA liability for conducting ordinary "registrar services".
Brands have to prioritize what they are going to spend the effort to go after.
Pointing to what other people are doing is generally not a good way to figure out what the law is. I'm pretty sure that half the traffic on the New Jersey State Turnpike is going over the speed limit. If you get pulled over, that fact is not going to help.
It makes me wonder if dropcatching services are exempt from being held responsible for selling such names through possibly their TOS, as bidders have to take responsibility not to bid on TM domains?
As above, you are responsible for what you do. Other people are responsible for what they do. Worrying about what other people do - whether it is law, morality, or anything else - is a good way to avoid self-improvement.
If Google was aware of the GoogleChromeUpdates.com auction, are they supposed to win the domain at auction to limit any possible security concerns? If they do win it, does google have a sound legal case to come after DropCatch, or other bidders from the auction who drove the price up? If Google wasn't aware of the auction, but became aware of the sale price, who is more liable if Google wants to make an example of somebody?
First rule - sue everyone.
The basic US law is 15 USC 1125(d):
A person shall be liable in a civil action by the owner of a mark, including a personal name which is protected as a mark under this section, if, without regard to the goods or services of the parties, that person -
(i) has a bad faith intent to profit from that mark, including a personal name which is protected as a mark under this section; and
(ii) registers, traffics in, or uses a domain name that -
(I) in the case of a mark that is distinctive at the time of registration of the domain name, is identical or confusingly similar to that mark;
(II) in the case of a famous mark that is famous at the time of registration of the domain name, is identical or confusingly similar to or dilutive of that mark; or
(III) is a trademark, word, or name protected by reason of (special provisions relating to 'Olympic' names).
Notice that "registers", "traffics in" or "uses" are three distinct acts.
So, in 15 USC 1114, we have this:
(iii) A domain name registrar, a domain name registry, or other domain name registration authority shall not be liable for damages under this section for the registration or maintenance of a domain name for another absent a showing of bad faith intent to profit from such registration or maintenance of the domain name.
The most interesting case of registrar immunity is Academy of Motion Picture Arts and Sciences v. GoDaddy.com Inc. on the question of whether GoDaddy had a "
bad faith intent to profit from such registration or maintenance of the domain name" in relation to domain names registered by GoDaddy customers, and parked by GoDaddy's automated system.
Here's a summary of what went on in that one:
http://www.dailyreportingsuite.com/...scar_marks_resolved_and_the_winner_is_godaddy
Unlike the situation on a message board where people think these are simple "yes or no" types of questions, the actual decision is 129 pages long:
http://business.cch.com/ipld/AMPASGoDaddy20150910.pdf - mainly because the decision includes a long list of the hundreds of domain names at issue.
