To prevent spam and other attacks we've created a few limits on the site. We've set the limits pretty high so you may never see them if you're using the site normally.
This limit is currently set at 200 hearts per hour. That means you can fill up to 10 pages on your heart in 60 minutes. 10 pages is a lot of images, we think it's pretty reasonable.
If you're constantly reaching this limit, we're glad you are enjoying We Heart It. But maybe you could pay more attention to what you are hearting and choose only the best pictures. Hearting more images than that in such a short period of time causes a heavy load on our servers and makes the site slower for everyone. I'm sure you wouldn't want that to happen.
When you reach the limit you'll see a warning message and you won't be able to heart for a few minutes. But don't worry, this is not a permanent block.