I've been avoiding SourceForge myself for a while now, but others are starting to report about their bad deeds as well.
http://www.howtogeek.com/218764/warning-don%E2%80%99t-download-software-from-sourceforge-if-you-can-help-it/
It's not so much Tucows themselves as they aren't the ones making the software or necessarily adding the crap into the software but the software developer.
Here is a good article discussing this very issue, they used Download.com as an example but it isn't just them that are effected by this...