One of the downsides of running some the of the largest advertising networks on the Internet is that there’s always going to be people looking to pollute those networks with their crappy ads. According to Google, it purged nearly 800 million of these crappy ads from its networks last year, which is almost a 50% increase from the year prior. The company has more than 1,000 employees dedicated to finding and removing these ads, and this year it intends to put more focus on fighting bots and malware, and will work even harder to ensure that ads aren’t trying to mislead viewers.