They haven't actually removed their anti fraud guarantee. If you read the wording it was never there in the first place. It isn't like igg would refund users if there perks never showed up. The old wording basically said that their system would detect
all fraud which could leave igg in a tight spot if lawyers ever got involved.
The actual part that seems to "protect"
users is still there.
Indiegogo requires campaign owners to fufill their Perks as a part of our Terms of Service. Perks are manged solely by campaign owners; we do not guarantee or take any legal responsibility for Perk fulfillment. Contributors can use our Terms of Service as a document in the court of law, should you choose to take legal action against a campaign owner for failing to fulfill a Perk.
Though igg say (and always have) that its up to the users to take action against campaign owners, but the old wording could also mean that if something slipped though igg's check they have bascially said "Yup, this checks out" when igg couldn't possibly to that with every campaign that goes though the site.