In the US Hold harmless refers to accepting liability for ones actions which cause claims for damages to be brought on another person or entity.
Indemnify refers to paying for any damages awarded to that other party.
It may seem redundant but it merely reflects the two prongs of the issue, liability and paying for it.
But the dictionaries -- and here I'm referring to Garner's A Dictionary of Modern Legal Usage
and Black's Law Dictionary (5th ed.)
-- give these BUT ALSO purely redundant
definitions. Actually, the former gives "hold harmless;" as one, among several; the latter
is what says that a preposition "for/against" is called for. But note that the clause at issue
here had no indemnify from/for
particulars, and so IMO is overly vague.
In the situation here, I might post something that causes offense to some
third party, who sues IGKT.net:
1) by agreement does the clause say that I will recompense IGKT.net
for any losses;
1b) does it suggest that (all) other users should contribute, too?
2) or does it say rather that the suit is wrongly aimed by the third
party, who is part of the agreement, and must not seek redress
vs. IGKT.net, only (somehow) against me, the poster?
I agree that in practicality all of the above seems beyond the realm
of possibility (though, egads, wild lawsuits are surely not -- I'm not
sure e.g. of the status of the some-time "judge" who sued a cleaners
for some $50million (10^^6) over lost or botched pants (which sadly
got into court system and though overruled did put the Korean cleaners
out of business).