Campaign owners can now place limits on the amounts people can contribute to their campaigns.
Why would someone want to limit the contribution amounts?
By default, the smallest amount someone can contribute is $2.00 USD (or equivalent on your currency). Some people don't want to accept such a small amount, so they can use this feature to make the minimum amount $5.00 instead (or any other amount, really).
By default, the largest amount someone can contribute at one time is $10,000 through PayPal or $12,500 through WePay. Some organizations (political organizations, for example) aren't allowed to accept more than a certain amount of money from a single contributor, so they can use this feature to make sure they're not violating any of the fundraising regulations they need to abide by.
Here's how to set up the feature:
Go to your campaign's Edit page. Click the Edit link in the black NavBar along the top of your campaign page.
On the Edit page, click the Funding & Deadline tab down the left side.
Scroll to the bottom and look in the "Payment limits" section. Check the appropriate box and enter an amount, then click Save changes at the bottom, and you're done!