When Web Crawlers Cross the Legal Line: Big Data Insights & Risk Guidance

Crawler technology, a front‑end method for acquiring website data, has become extremely popular in the era of big‑data applications, but careless use has led to numerous legal cases. While the technology itself is neutral, its misuse can be punishable.

Many lawyers mistakenly conflate targeted crawlers with search‑engine bots, leading to outdated or incorrect definitions. In reality, targeted crawlers—referred here as "website information automated collection technology"—focus on parsing a specific website to batch‑retrieve the data displayed on the front end.

The technique is not sophisticated nor a "hacker" skill; even a beginner can master it. Currently, mainstream crawlers fall into two categories:

1. After the website renders, use regular expressions to match front‑end code and extract the needed information.

2. Bypass rendering (or perform minimal rendering) and directly call the site’s API interfaces.

More advanced crawlers skip static page rendering and invoke dynamic APIs for maximum efficiency. Some legal professionals view this as bypassing verification mechanisms, but the majority of sites (about 99%) expose their APIs openly.

Legal practitioners should first recognize two key points: (1) crawlers only retrieve information that is publicly available (or made available to the crawler); (2) crawlers do not obtain backend permissions of the target site. Violating either condition turns the activity into illegal hacking.

Using Python, a sample search of court judgments up to 2019‑11‑15 identified 22 relevant cases (keywords: crawler, data scraping, data crawling). The following charts illustrate the distribution of offenses and regional case locations.

The earliest judgment dates to 2014‑07‑07 and the latest to 2019‑10‑28. The data shows that "infringement of personal information" is the most frequent charge, while "illegal acquisition of computer information system data" carries the longest sentences.

A notable case is the "Shanghai Shengpin Network Technology Co., etc. illegal acquisition of computer information system data" judgment, popularly known as the "Today's Headlines crawler case". The author references another article for deeper analysis.

For programmers, big‑data professionals, or crawler service providers, the following precautions are recommended:

1. Do not crawl personal information or citizen privacy data.

2. Do not trade scraped commercial data without authorization.

3. Handle copyrighted content cautiously; commercial use without permission is illegal.

Authorized crawling does not violate the law, but re‑using the data beyond the granted scope can be illegal. Even when user consent is obtained for data collection, subsequent unauthorized use—especially for profit—constitutes a serious violation.

Finally, the article stresses that merely accessing publicly available information is not automatically illegal, yet websites must also be held accountable for mishandling user data. The focus should be on the legality of the acquisition method rather than demonizing crawler technology, and civil disputes should not be conflated with criminal prosecution.