This is all due to fraudulent ICOs. At current time 9 out of 10 ICOs are total scam. They do a fundraising and spend nothing on anything except for roaming around and spending in useless things. And it's a good move from social sites to block those ads until we have regulations of the ICOs.
Not all ICOs are the same. We are working on solving a
real global issues such as performing novel biomerical research for developing a cost effective cure solution for AIDS, allowing access to the therapy where access to traditional costly HIV therapies is restricted by social and/or economic limitations.
https://bitcointalk.org/index.php?topic=3145049.msg32512837#msg32512837