updated selectors, and a greater quantity of selectors. For example, the Floppy Moose style sheet originally contained 40 lines of CSS. In 2022, Easylist contains thousands of CSS selectors. In contrast to the general example above, below is one of the many specific CSS selectors from Easylist (2022). a[href^="https://topoffers.com/"][href*="/?pid="] In January 2016, Brave, a free, ad-blocking browser for Mac, PC, Android, and iOS devices was launched. Brave users can optionally enable Brave's own ad network to earn Basic Attention Tokens (BATs), a type of cryptocurrency, which can be sent as micro-payments to publishers. At the beginning of 2018, Google confirmed that the built-in ad blocker for the Chrome/Chromium browsers would go live on 15 February: this ad blocker only blocks certain ads as specified by the Better Ads Standard (defined by the Coalition for Better Ads, in which Google itself is a board member). This built-in ad blocking mechanism is disputed because it could unfairly benefit Google's advertising itself. In 2019, both Apple and Google began to make changes to their web browsers' extension systems which encourage the use of declarative content blocking using pre-determined filters processed by the web browser, rather than filters processed at runtime by the extension. Both vendors have imposed limits on the number of entries that may be included in these lists, which have led to (especially in the case of Chrome) allegations that these changes are being made to inhibit the effectiveness of ad blockers. External programs A number of external software applications offer ad filtering as a primary or additional feature. A traditional solution is to customize an HTTP proxy (or web proxy) to filter content. These programs work by caching and filtering content before it is displayed in a user's browser. This provides an opportunity to remove not only ads but also content that may be offensive, inappropriate, or even malicious (Drive-by download). Popular proxy software which blocks content effectively include Netnanny, Privoxy, Squid, and some content-control software. The main advantage of the method is freedom from implementation limitations (browser, working techniques) and centralization of control (the proxy can be used by many users). Proxies are very good at filtering ads, but they have several limitations compared to browser-based solutions. For proxies, it is difficult to filter Transport Layer Security (SSL) (https://) traffic and full webpage context is not available to the filter. As well, proxies find it difficult to filter JavaScript-generated