Roll20.net is a company that engages in fraudulent business practices through using social bookmarking websites like Reddit and abusing moderator positions to stifle online criticism and critique of their software. While this falling afoul of the terms of use of the website is not a legal issue, it is certainly a moral issue to say the least. They seem to be interested in banning users that say anything negative about their product or banning users proactively to prevent them from saying anything bad if they so much as blink in the wrong direction. Their customer communication is absolutely horrendous and they do not have any interest in actually improving the product, just adding more content to it to appeal to a group of consumer 'whales' that are willing to spend thousands on a single product.
My DM uses roll20 in our campaign. Since we do our campaigns online since the members of the campaign our in different states, he likes to use the interactive map. That is so cool! Roll20 was a little har to figure out at first and there are some things I still can't figure out with the site. But I like how it has made it easier to play D&D slightly easier to play online.