"Crumbs" is a noun (名词) here. "Bread crumbs" is a reference to the famous fairytale of Hansel and Gretel, who left bread crumbs in their trail so that they can follow the crumbs home and won't get lost in the woods. So the sentence is trying to say that when you're on the internet, you leave behind pieces of personal information that strangers can find and put together to have an idea of who you are, where you are/live etc.

Bread crumbs=麵包屑(名詞) Digital=數位 源自童話故事糖果屋的說法，麵包屑在此指線索、蛛絲馬跡 Digital breadcrumbs是指網路上的蛛絲馬跡 整句話的意思就是指 藉由妳在網路上留下的蛛絲馬跡，讓陌生人能更輕易拼湊出妳是誰、住在哪裡以及妳是什麼樣的人。

The digital bread crumbs, which you leave everywhere, make it easy for strangers to reconstruct who you are, where you are and what you like.

放在主语digital bread后面，又加了s，肯定是动词吧~我理解的意思是：数字化生活中的你就像面包屑一些散落在各个地方，很容易根据这些屑末重构出原始的你的数据~